X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/7ddcb079202367355dddccdfa4318e57d50318be..4ba76501152d51ccb5647018f3192c6096367d48:/bsd/miscfs/specfs/spec_vnops.c diff --git a/bsd/miscfs/specfs/spec_vnops.c b/bsd/miscfs/specfs/spec_vnops.c index 52cf1c806..300894634 100644 --- a/bsd/miscfs/specfs/spec_vnops.c +++ b/bsd/miscfs/specfs/spec_vnops.c @@ -1,8 +1,8 @@ /* - * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2019 Apple Computer, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,7 +22,7 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ @@ -81,92 +81,167 @@ #include #include #include +#include #include #include +#include + #include #include +#include +#include +#include +#include +#include + +#include #include +#include /* XXX following three prototypes should be in a header file somewhere */ -extern dev_t chrtoblk(dev_t dev); -extern int iskmemdev(dev_t dev); -extern int bpfkqfilter(dev_t dev, struct knote *kn); -extern int ptsd_kqfilter(dev_t dev, struct knote *kn); +extern dev_t chrtoblk(dev_t dev); +extern boolean_t iskmemdev(dev_t dev); +extern int bpfkqfilter(dev_t dev, struct knote *kn); +extern int ptsd_kqfilter(dev_t, struct knote *); +extern int ptmx_kqfilter(dev_t, struct knote *); struct vnode *speclisth[SPECHSZ]; /* symbolic sleep message strings for devices */ -char devopn[] = "devopn"; -char devio[] = "devio"; -char devwait[] = "devwait"; -char devin[] = "devin"; -char devout[] = "devout"; -char devioc[] = "devioc"; -char devcls[] = "devcls"; +char devopn[] = "devopn"; +char devio[] = "devio"; +char devwait[] = "devwait"; +char devin[] = "devin"; +char devout[] = "devout"; +char devioc[] = "devioc"; +char devcls[] = "devcls"; #define VOPFUNC int (*)(void *) -int (**spec_vnodeop_p)(void *); -struct vnodeopv_entry_desc spec_vnodeop_entries[] = { - { &vnop_default_desc, (VOPFUNC)vn_default_error }, - { &vnop_lookup_desc, (VOPFUNC)spec_lookup }, /* lookup */ - { &vnop_create_desc, (VOPFUNC)err_create }, /* create */ - { &vnop_mknod_desc, (VOPFUNC)err_mknod }, /* mknod */ - { &vnop_open_desc, (VOPFUNC)spec_open }, /* open */ - { &vnop_close_desc, (VOPFUNC)spec_close }, /* close */ - { &vnop_access_desc, (VOPFUNC)spec_access }, /* access */ - { &vnop_getattr_desc, (VOPFUNC)spec_getattr }, /* getattr */ - { &vnop_setattr_desc, (VOPFUNC)spec_setattr }, /* setattr */ - { &vnop_read_desc, (VOPFUNC)spec_read }, /* read */ - { &vnop_write_desc, (VOPFUNC)spec_write }, /* write */ - { &vnop_ioctl_desc, (VOPFUNC)spec_ioctl }, /* ioctl */ - { &vnop_select_desc, (VOPFUNC)spec_select }, /* select */ - { &vnop_revoke_desc, (VOPFUNC)nop_revoke }, /* revoke */ - { &vnop_mmap_desc, (VOPFUNC)err_mmap }, /* mmap */ - { &vnop_fsync_desc, (VOPFUNC)spec_fsync }, /* fsync */ - { &vnop_remove_desc, (VOPFUNC)err_remove }, /* remove */ - { &vnop_link_desc, (VOPFUNC)err_link }, /* link */ - { &vnop_rename_desc, (VOPFUNC)err_rename }, /* rename */ - { &vnop_mkdir_desc, (VOPFUNC)err_mkdir }, /* mkdir */ - { &vnop_rmdir_desc, (VOPFUNC)err_rmdir }, /* rmdir */ - { &vnop_symlink_desc, (VOPFUNC)err_symlink }, /* symlink */ - { &vnop_readdir_desc, (VOPFUNC)err_readdir }, /* readdir */ - { &vnop_readlink_desc, (VOPFUNC)err_readlink }, /* readlink */ - { &vnop_inactive_desc, (VOPFUNC)nop_inactive }, /* inactive */ - { &vnop_reclaim_desc, (VOPFUNC)nop_reclaim }, /* reclaim */ - { &vnop_strategy_desc, (VOPFUNC)spec_strategy }, /* strategy */ - { &vnop_pathconf_desc, (VOPFUNC)spec_pathconf }, /* pathconf */ - { &vnop_advlock_desc, (VOPFUNC)err_advlock }, /* advlock */ - { &vnop_bwrite_desc, (VOPFUNC)spec_bwrite }, /* bwrite */ - { &vnop_pagein_desc, (VOPFUNC)err_pagein }, /* Pagein */ - { &vnop_pageout_desc, (VOPFUNC)err_pageout }, /* Pageout */ - { &vnop_copyfile_desc, (VOPFUNC)err_copyfile }, /* Copyfile */ - { &vnop_blktooff_desc, (VOPFUNC)spec_blktooff }, /* blktooff */ - { &vnop_offtoblk_desc, (VOPFUNC)spec_offtoblk }, /* offtoblk */ - { &vnop_blockmap_desc, (VOPFUNC)spec_blockmap }, /* blockmap */ - { (struct vnodeop_desc*)NULL, (int(*)())NULL } +int(**spec_vnodeop_p)(void *); +const struct vnodeopv_entry_desc spec_vnodeop_entries[] = { + { .opve_op = &vnop_default_desc, .opve_impl = (VOPFUNC)vn_default_error }, + { .opve_op = &vnop_lookup_desc, .opve_impl = (VOPFUNC)spec_lookup }, /* lookup */ + { .opve_op = &vnop_create_desc, .opve_impl = (VOPFUNC)err_create }, /* create */ + { .opve_op = &vnop_mknod_desc, .opve_impl = (VOPFUNC)err_mknod }, /* mknod */ + { .opve_op = &vnop_open_desc, .opve_impl = (VOPFUNC)spec_open }, /* open */ + { .opve_op = &vnop_close_desc, .opve_impl = (VOPFUNC)spec_close }, /* close */ + { .opve_op = &vnop_access_desc, .opve_impl = (VOPFUNC)spec_access }, /* access */ + { .opve_op = &vnop_getattr_desc, .opve_impl = (VOPFUNC)spec_getattr }, /* getattr */ + { .opve_op = &vnop_setattr_desc, .opve_impl = (VOPFUNC)spec_setattr }, /* setattr */ + { .opve_op = &vnop_read_desc, .opve_impl = (VOPFUNC)spec_read }, /* read */ + { .opve_op = &vnop_write_desc, .opve_impl = (VOPFUNC)spec_write }, /* write */ + { .opve_op = &vnop_ioctl_desc, .opve_impl = (VOPFUNC)spec_ioctl }, /* ioctl */ + { .opve_op = &vnop_select_desc, .opve_impl = (VOPFUNC)spec_select }, /* select */ + { .opve_op = &vnop_revoke_desc, .opve_impl = (VOPFUNC)nop_revoke }, /* revoke */ + { .opve_op = &vnop_mmap_desc, .opve_impl = (VOPFUNC)err_mmap }, /* mmap */ + { .opve_op = &vnop_fsync_desc, .opve_impl = (VOPFUNC)spec_fsync }, /* fsync */ + { .opve_op = &vnop_remove_desc, .opve_impl = (VOPFUNC)err_remove }, /* remove */ + { .opve_op = &vnop_link_desc, .opve_impl = (VOPFUNC)err_link }, /* link */ + { .opve_op = &vnop_rename_desc, .opve_impl = (VOPFUNC)err_rename }, /* rename */ + { .opve_op = &vnop_mkdir_desc, .opve_impl = (VOPFUNC)err_mkdir }, /* mkdir */ + { .opve_op = &vnop_rmdir_desc, .opve_impl = (VOPFUNC)err_rmdir }, /* rmdir */ + { .opve_op = &vnop_symlink_desc, .opve_impl = (VOPFUNC)err_symlink }, /* symlink */ + { .opve_op = &vnop_readdir_desc, .opve_impl = (VOPFUNC)err_readdir }, /* readdir */ + { .opve_op = &vnop_readlink_desc, .opve_impl = (VOPFUNC)err_readlink }, /* readlink */ + { .opve_op = &vnop_inactive_desc, .opve_impl = (VOPFUNC)nop_inactive }, /* inactive */ + { .opve_op = &vnop_reclaim_desc, .opve_impl = (VOPFUNC)nop_reclaim }, /* reclaim */ + { .opve_op = &vnop_strategy_desc, .opve_impl = (VOPFUNC)spec_strategy }, /* strategy */ + { .opve_op = &vnop_pathconf_desc, .opve_impl = (VOPFUNC)spec_pathconf }, /* pathconf */ + { .opve_op = &vnop_advlock_desc, .opve_impl = (VOPFUNC)err_advlock }, /* advlock */ + { .opve_op = &vnop_bwrite_desc, .opve_impl = (VOPFUNC)spec_bwrite }, /* bwrite */ + { .opve_op = &vnop_pagein_desc, .opve_impl = (VOPFUNC)err_pagein }, /* Pagein */ + { .opve_op = &vnop_pageout_desc, .opve_impl = (VOPFUNC)err_pageout }, /* Pageout */ + { .opve_op = &vnop_copyfile_desc, .opve_impl = (VOPFUNC)err_copyfile }, /* Copyfile */ + { .opve_op = &vnop_blktooff_desc, .opve_impl = (VOPFUNC)spec_blktooff }, /* blktooff */ + { .opve_op = &vnop_offtoblk_desc, .opve_impl = (VOPFUNC)spec_offtoblk }, /* offtoblk */ + { .opve_op = &vnop_blockmap_desc, .opve_impl = (VOPFUNC)spec_blockmap }, /* blockmap */ + { .opve_op = (struct vnodeop_desc*)NULL, .opve_impl = (int (*)(void *))NULL } }; -struct vnodeopv_desc spec_vnodeop_opv_desc = - { &spec_vnodeop_p, spec_vnodeop_entries }; +const struct vnodeopv_desc spec_vnodeop_opv_desc = +{ .opv_desc_vector_p = &spec_vnodeop_p, .opv_desc_ops = spec_vnodeop_entries }; static void set_blocksize(vnode_t, dev_t); +#define LOWPRI_TIER1_WINDOW_MSECS 25 +#define LOWPRI_TIER2_WINDOW_MSECS 100 +#define LOWPRI_TIER3_WINDOW_MSECS 500 + +#define LOWPRI_TIER1_IO_PERIOD_MSECS 40 +#define LOWPRI_TIER2_IO_PERIOD_MSECS 85 +#define LOWPRI_TIER3_IO_PERIOD_MSECS 200 + +#define LOWPRI_TIER1_IO_PERIOD_SSD_MSECS 5 +#define LOWPRI_TIER2_IO_PERIOD_SSD_MSECS 15 +#define LOWPRI_TIER3_IO_PERIOD_SSD_MSECS 25 + + +int throttle_windows_msecs[THROTTLE_LEVEL_END + 1] = { + 0, + LOWPRI_TIER1_WINDOW_MSECS, + LOWPRI_TIER2_WINDOW_MSECS, + LOWPRI_TIER3_WINDOW_MSECS, +}; + +int throttle_io_period_msecs[THROTTLE_LEVEL_END + 1] = { + 0, + LOWPRI_TIER1_IO_PERIOD_MSECS, + LOWPRI_TIER2_IO_PERIOD_MSECS, + LOWPRI_TIER3_IO_PERIOD_MSECS, +}; + +int throttle_io_period_ssd_msecs[THROTTLE_LEVEL_END + 1] = { + 0, + LOWPRI_TIER1_IO_PERIOD_SSD_MSECS, + LOWPRI_TIER2_IO_PERIOD_SSD_MSECS, + LOWPRI_TIER3_IO_PERIOD_SSD_MSECS, +}; + + +int throttled_count[THROTTLE_LEVEL_END + 1]; struct _throttle_io_info_t { - struct timeval last_normal_IO_timestamp; - struct timeval last_IO_timestamp; - SInt32 numthreads_throttling; - SInt32 refcnt; - SInt32 alloc; + lck_mtx_t throttle_lock; + + struct timeval throttle_last_write_timestamp; + struct timeval throttle_min_timer_deadline; + struct timeval throttle_window_start_timestamp[THROTTLE_LEVEL_END + 1]; /* window starts at both the beginning and completion of an I/O */ + struct timeval throttle_last_IO_timestamp[THROTTLE_LEVEL_END + 1]; + pid_t throttle_last_IO_pid[THROTTLE_LEVEL_END + 1]; + struct timeval throttle_start_IO_period_timestamp[THROTTLE_LEVEL_END + 1]; + int32_t throttle_inflight_count[THROTTLE_LEVEL_END + 1]; + + TAILQ_HEAD(, uthread) throttle_uthlist[THROTTLE_LEVEL_END + 1]; /* Lists of throttled uthreads */ + int throttle_next_wake_level; + + thread_call_t throttle_timer_call; + int32_t throttle_timer_ref; + int32_t throttle_timer_active; + + int32_t throttle_io_count; + int32_t throttle_io_count_begin; + int *throttle_io_periods; + uint32_t throttle_io_period_num; + + int32_t throttle_refcnt; + int32_t throttle_alloc; + int32_t throttle_disabled; + int32_t throttle_is_fusion_with_priority; }; struct _throttle_io_info_t _throttle_io_info[LOWPRI_MAX_NUM_DEV]; -static void throttle_info_update_internal(void *throttle_info, int flags, boolean_t isssd); + +int lowpri_throttle_enabled = 1; +static void throttle_info_end_io_internal(struct _throttle_io_info_t *info, int throttle_level); +static int throttle_info_update_internal(struct _throttle_io_info_t *info, uthread_t ut, int flags, boolean_t isssd, boolean_t inflight, struct bufattr *bap); +static int throttle_get_thread_throttle_level(uthread_t ut); +static int throttle_get_thread_throttle_level_internal(uthread_t ut, int io_tier); +void throttle_info_mount_reset_period(mount_t mp, int isssd); /* * Trivial lookup routine that always fails. @@ -174,44 +249,43 @@ static void throttle_info_update_internal(void *throttle_info, int flags, boolea int spec_lookup(struct vnop_lookup_args *ap) { - *ap->a_vpp = NULL; - return (ENOTDIR); + return ENOTDIR; } static void set_blocksize(struct vnode *vp, dev_t dev) { - int (*size)(dev_t); - int rsize; + int (*size)(dev_t); + int rsize; - if ((major(dev) < nblkdev) && (size = bdevsw[major(dev)].d_psize)) { - rsize = (*size)(dev); - if (rsize <= 0) /* did size fail? */ - vp->v_specsize = DEV_BSIZE; - else - vp->v_specsize = rsize; - } - else - vp->v_specsize = DEV_BSIZE; + if ((major(dev) < nblkdev) && (size = bdevsw[major(dev)].d_psize)) { + rsize = (*size)(dev); + if (rsize <= 0) { /* did size fail? */ + vp->v_specsize = DEV_BSIZE; + } else { + vp->v_specsize = rsize; + } + } else { + vp->v_specsize = DEV_BSIZE; + } } void set_fsblocksize(struct vnode *vp) { - if (vp->v_type == VBLK) { dev_t dev = (dev_t)vp->v_rdev; int maj = major(dev); - if ((u_int)maj >= (u_int)nblkdev) + if ((u_int)maj >= (u_int)nblkdev) { return; + } vnode_lock(vp); set_blocksize(vp, dev); vnode_unlock(vp); } - } @@ -231,40 +305,42 @@ spec_open(struct vnop_open_args *ap) /* * Don't allow open if fs is mounted -nodev. */ - if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) - return (ENXIO); + if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) { + return ENXIO; + } switch (vp->v_type) { - case VCHR: - if ((u_int)maj >= (u_int)nchrdev) - return (ENXIO); + if ((u_int)maj >= (u_int)nchrdev) { + return ENXIO; + } if (cred != FSCRED && (ap->a_mode & FWRITE)) { +#if 0 /* * When running in very secure mode, do not allow * opens for writing of any disk character devices. */ - if (securelevel >= 2 && isdisk(dev, VCHR)) - return (EPERM); + if (securelevel >= 2 && isdisk(dev, VCHR)) { + return EPERM; + } +#endif + + /* Never allow writing to /dev/mem or /dev/kmem */ + if (iskmemdev(dev)) { + return EPERM; + } /* - * When running in secure mode, do not allow opens - * for writing of /dev/mem, /dev/kmem, or character - * devices whose corresponding block devices are - * currently mounted. + * When running in secure mode, do not allow opens for + * writing of character devices whose corresponding block + * devices are currently mounted. */ if (securelevel >= 1) { - if ((bdev = chrtoblk(dev)) != NODEV && check_mountedon(bdev, VBLK, &error)) - return (error); - if (iskmemdev(dev)) - return (EPERM); + if ((bdev = chrtoblk(dev)) != NODEV && check_mountedon(bdev, VBLK, &error)) { + return error; + } } } - if (cdevsw[maj].d_type == D_TTY) { - vnode_lock(vp); - vp->v_flag |= VISTTY; - vnode_unlock(vp); - } - + devsw_lock(dev, S_IFCHR); error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, p); @@ -275,13 +351,13 @@ spec_open(struct vnop_open_args *ap) devsw_unlock(dev, S_IFCHR); if (error == 0 && cdevsw[maj].d_type == D_DISK && !vp->v_un.vu_specinfo->si_initted) { - int isssd = 0; + int isssd = 0; uint64_t throttle_mask = 0; uint32_t devbsdunit = 0; if (VNOP_IOCTL(vp, DKIOCGETTHROTTLEMASK, (caddr_t)&throttle_mask, 0, NULL) == 0) { - - if (VNOP_IOCTL(vp, DKIOCISSOLIDSTATE, (caddr_t)&isssd, 0, ap->a_context) == 0) { + if (throttle_mask != 0 && + VNOP_IOCTL(vp, DKIOCISSOLIDSTATE, (caddr_t)&isssd, 0, ap->a_context) == 0) { /* * as a reasonable approximation, only use the lowest bit of the mask * to generate a disk unit number @@ -289,7 +365,7 @@ spec_open(struct vnop_open_args *ap) devbsdunit = num_trailing_0(throttle_mask); vnode_lock(vp); - + vp->v_un.vu_specinfo->si_isssd = isssd; vp->v_un.vu_specinfo->si_devbsdunit = devbsdunit; vp->v_un.vu_specinfo->si_throttle_mask = throttle_mask; @@ -305,24 +381,27 @@ spec_open(struct vnop_open_args *ap) vnode_unlock(vp); } } - return (error); + return error; case VBLK: - if ((u_int)maj >= (u_int)nblkdev) - return (ENXIO); + if ((u_int)maj >= (u_int)nblkdev) { + return ENXIO; + } /* * When running in very secure mode, do not allow * opens for writing of any disk block devices. */ if (securelevel >= 2 && cred != FSCRED && - (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK) - return (EPERM); + (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK) { + return EPERM; + } /* * Do not allow opens of block devices that are * currently mounted. */ - if ( (error = vfs_mountedon(vp)) ) - return (error); + if ((error = vfs_mountedon(vp))) { + return error; + } devsw_lock(dev, S_IFBLK); error = (*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, p); @@ -332,47 +411,47 @@ spec_open(struct vnop_open_args *ap) devsw_unlock(dev, S_IFBLK); if (!error) { - u_int64_t blkcnt; - u_int32_t blksize; + u_int64_t blkcnt; + u_int32_t blksize; int setsize = 0; u_int32_t size512 = 512; - if (!VNOP_IOCTL(vp, DKIOCGETBLOCKSIZE, (caddr_t)&blksize, 0, ap->a_context)) { + if (!VNOP_IOCTL(vp, DKIOCGETBLOCKSIZE, (caddr_t)&blksize, 0, ap->a_context)) { /* Switch to 512 byte sectors (temporarily) */ if (!VNOP_IOCTL(vp, DKIOCSETBLOCKSIZE, (caddr_t)&size512, FWRITE, ap->a_context)) { - /* Get the number of 512 byte physical blocks. */ - if (!VNOP_IOCTL(vp, DKIOCGETBLOCKCOUNT, (caddr_t)&blkcnt, 0, ap->a_context)) { + /* Get the number of 512 byte physical blocks. */ + if (!VNOP_IOCTL(vp, DKIOCGETBLOCKCOUNT, (caddr_t)&blkcnt, 0, ap->a_context)) { setsize = 1; - } + } } /* If it doesn't set back, we can't recover */ - if (VNOP_IOCTL(vp, DKIOCSETBLOCKSIZE, (caddr_t)&blksize, FWRITE, ap->a_context)) - error = ENXIO; - } + if (VNOP_IOCTL(vp, DKIOCSETBLOCKSIZE, (caddr_t)&blksize, FWRITE, ap->a_context)) { + error = ENXIO; + } + } vnode_lock(vp); - set_blocksize(vp, dev); + set_blocksize(vp, dev); - /* - * Cache the size in bytes of the block device for later - * use by spec_write(). - */ - if (setsize) + /* + * Cache the size in bytes of the block device for later + * use by spec_write(). + */ + if (setsize) { vp->v_specdevsize = blkcnt * (u_int64_t)size512; - else - vp->v_specdevsize = (u_int64_t)0; /* Default: Can't get */ - + } else { + vp->v_specdevsize = (u_int64_t)0; /* Default: Can't get */ + } vnode_unlock(vp); - } - return(error); + return error; default: - panic("spec_open type"); + panic("spec_open type"); } - return (0); + return 0; } /* @@ -386,61 +465,106 @@ spec_read(struct vnop_read_args *ap) struct buf *bp; daddr64_t bn, nextbn; long bsize, bscale; - int devBlockSize=0; + int devBlockSize = 0; int n, on; int error = 0; dev_t dev; #if DIAGNOSTIC - if (uio->uio_rw != UIO_READ) + if (uio->uio_rw != UIO_READ) { panic("spec_read mode"); - if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) + } + if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) { panic("spec_read proc"); + } #endif - if (uio_resid(uio) == 0) - return (0); + if (uio_resid(uio) == 0) { + return 0; + } switch (vp->v_type) { - case VCHR: - if (cdevsw[major(vp->v_rdev)].d_type == D_DISK && vp->v_un.vu_specinfo->si_throttleable) { - struct _throttle_io_info_t *throttle_info; + { + struct _throttle_io_info_t *throttle_info = NULL; + int thread_throttle_level; + uint64_t blkno = 0; + uint32_t iolen = 0; + int ddisk = 0; + int ktrace_code = DKIO_READ; + devBlockSize = vp->v_specsize; + uintptr_t our_id; + if (cdevsw[major(vp->v_rdev)].d_type == D_DISK) { + ddisk = 1; + } + + if (ddisk && vp->v_un.vu_specinfo->si_throttleable) { throttle_info = &_throttle_io_info[vp->v_un.vu_specinfo->si_devbsdunit]; + thread_throttle_level = throttle_info_update_internal(throttle_info, NULL, 0, vp->v_un.vu_specinfo->si_isssd, TRUE, NULL); + } + + if (kdebug_enable && ddisk) { + if (devBlockSize == 0) { + devBlockSize = 512; // default sector size + } - throttle_info_update_internal(throttle_info, 0, vp->v_un.vu_specinfo->si_isssd); - } + if (uio_offset(uio) && devBlockSize) { + blkno = ((uint64_t) uio_offset(uio) / ((uint64_t)devBlockSize)); + } + iolen = (int) uio_resid(uio); + our_id = (uintptr_t)thread_tid(current_thread()); + KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON, + (FSDBG_CODE(DBG_DKRW, ktrace_code)) | DBG_FUNC_NONE, our_id, + vp->v_rdev, blkno, iolen, 0); + } error = (*cdevsw[major(vp->v_rdev)].d_read) - (vp->v_rdev, uio, ap->a_ioflag); + (vp->v_rdev, uio, ap->a_ioflag); + - return (error); + if (kdebug_enable && ddisk) { + uint32_t residual = (uint32_t)uio_resid(uio); + ktrace_code |= DKIO_DONE; + KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON, + (FSDBG_CODE(DBG_DKRW, ktrace_code)) | DBG_FUNC_NONE, our_id, + (uintptr_t)VM_KERNEL_ADDRPERM(vp), residual, error, 0); + } + + if (throttle_info) { + throttle_info_end_io_internal(throttle_info, thread_throttle_level); + } + + return error; + } case VBLK: - if (uio->uio_offset < 0) - return (EINVAL); + if (uio->uio_offset < 0) { + return EINVAL; + } dev = vp->v_rdev; devBlockSize = vp->v_specsize; - if (devBlockSize > PAGE_SIZE) - return (EINVAL); + if (devBlockSize > PAGE_SIZE) { + return EINVAL; + } - bscale = PAGE_SIZE / devBlockSize; + bscale = PAGE_SIZE / devBlockSize; bsize = bscale * devBlockSize; do { on = uio->uio_offset % bsize; - bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ (bscale - 1)); - + bn = (daddr64_t)((uio->uio_offset / devBlockSize) & ~(bscale - 1)); + if (vp->v_speclastr + bscale == bn) { - nextbn = bn + bscale; + nextbn = bn + bscale; error = buf_breadn(vp, bn, (int)bsize, &nextbn, - (int *)&bsize, 1, NOCRED, &bp); - } else - error = buf_bread(vp, bn, (int)bsize, NOCRED, &bp); + (int *)&bsize, 1, NOCRED, &bp); + } else { + error = buf_bread(vp, bn, (int)bsize, NOCRED, &bp); + } vnode_lock(vp); vp->v_speclastr = bn; @@ -448,26 +572,28 @@ spec_read(struct vnop_read_args *ap) n = bsize - buf_resid(bp); if ((on > n) || error) { - if (!error) - error = EINVAL; + if (!error) { + error = EINVAL; + } buf_brelse(bp); - return (error); + return error; } n = min((unsigned)(n - on), uio_resid(uio)); error = uiomove((char *)buf_dataptr(bp) + on, n, uio); - if (n + on == bsize) + if (n + on == bsize) { buf_markaged(bp); + } buf_brelse(bp); } while (error == 0 && uio_resid(uio) > 0 && n != 0); - return (error); + return error; default: panic("spec_read type"); } /* NOTREACHED */ - return (0); + return 0; } /* @@ -482,57 +608,101 @@ spec_write(struct vnop_write_args *ap) daddr64_t bn; int bsize, blkmask, bscale; int io_sync; - int devBlockSize=0; + int devBlockSize = 0; int n, on; int error = 0; dev_t dev; #if DIAGNOSTIC - if (uio->uio_rw != UIO_WRITE) + if (uio->uio_rw != UIO_WRITE) { panic("spec_write mode"); - if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) + } + if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) { panic("spec_write proc"); + } #endif switch (vp->v_type) { - case VCHR: - if (cdevsw[major(vp->v_rdev)].d_type == D_DISK && vp->v_un.vu_specinfo->si_throttleable) { - struct _throttle_io_info_t *throttle_info; + { + struct _throttle_io_info_t *throttle_info = NULL; + int thread_throttle_level; + dev = vp->v_rdev; + devBlockSize = vp->v_specsize; + uint32_t iolen = 0; + uint64_t blkno = 0; + int ddisk = 0; + int ktrace_code = 0; // write is implied; read must be OR'd in. + uintptr_t our_id; + + if (cdevsw[major(dev)].d_type == D_DISK) { + ddisk = 1; + } + if (ddisk && vp->v_un.vu_specinfo->si_throttleable) { throttle_info = &_throttle_io_info[vp->v_un.vu_specinfo->si_devbsdunit]; - throttle_info_update_internal(throttle_info, 0, vp->v_un.vu_specinfo->si_isssd); + thread_throttle_level = throttle_info_update_internal(throttle_info, NULL, 0, vp->v_un.vu_specinfo->si_isssd, TRUE, NULL); - microuptime(&throttle_info->last_IO_timestamp); - } + microuptime(&throttle_info->throttle_last_write_timestamp); + } + if (kdebug_enable && ddisk) { + if (devBlockSize == 0) { + devBlockSize = 512; // default sector size + } + if ((uio_offset(uio) != 0) && devBlockSize) { + blkno = ((uint64_t)uio_offset(uio)) / ((uint64_t)devBlockSize); + } + iolen = (int)uio_resid(uio); + our_id = (uintptr_t)thread_tid(current_thread()); + KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON, + (FSDBG_CODE(DBG_DKRW, ktrace_code)) | DBG_FUNC_NONE, our_id, + vp->v_rdev, blkno, iolen, 0); + } error = (*cdevsw[major(vp->v_rdev)].d_write) - (vp->v_rdev, uio, ap->a_ioflag); + (vp->v_rdev, uio, ap->a_ioflag); + + if (kdebug_enable && ddisk) { + //emit the I/O completion + uint32_t residual = (uint32_t)uio_resid(uio); + ktrace_code |= DKIO_DONE; + KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON, + (FSDBG_CODE(DBG_DKRW, ktrace_code)) | DBG_FUNC_NONE, our_id, + (uintptr_t)VM_KERNEL_ADDRPERM(vp), residual, error, 0); + } - return (error); + if (throttle_info) { + throttle_info_end_io_internal(throttle_info, thread_throttle_level); + } + + return error; + } case VBLK: - if (uio_resid(uio) == 0) - return (0); - if (uio->uio_offset < 0) - return (EINVAL); + if (uio_resid(uio) == 0) { + return 0; + } + if (uio->uio_offset < 0) { + return EINVAL; + } io_sync = (ap->a_ioflag & IO_SYNC); dev = (vp->v_rdev); devBlockSize = vp->v_specsize; - if (devBlockSize > PAGE_SIZE) - return(EINVAL); + if (devBlockSize > PAGE_SIZE) { + return EINVAL; + } - bscale = PAGE_SIZE / devBlockSize; + bscale = PAGE_SIZE / devBlockSize; blkmask = bscale - 1; bsize = bscale * devBlockSize; - + do { - bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ blkmask); + bn = (daddr64_t)((uio->uio_offset / devBlockSize) & ~blkmask); on = uio->uio_offset % bsize; n = min((unsigned)(bsize - on), uio_resid(uio)); @@ -550,48 +720,51 @@ spec_write(struct vnop_write_args *ap) if (n == bsize && vp->v_specdevsize != (u_int64_t)0 && (uio->uio_offset + (u_int64_t)n) > vp->v_specdevsize) { - /* reduce the size of the read to what is there */ - n = (uio->uio_offset + (u_int64_t)n) - vp->v_specdevsize; + /* reduce the size of the read to what is there */ + n = (uio->uio_offset + (u_int64_t)n) - vp->v_specdevsize; } - if (n == bsize) - bp = buf_getblk(vp, bn, bsize, 0, 0, BLK_WRITE); - else - error = (int)buf_bread(vp, bn, bsize, NOCRED, &bp); + if (n == bsize) { + bp = buf_getblk(vp, bn, bsize, 0, 0, BLK_WRITE); + } else { + error = (int)buf_bread(vp, bn, bsize, NOCRED, &bp); + } /* Translate downstream error for upstream, if needed */ - if (!error) + if (!error) { error = (int)buf_error(bp); + } if (error) { buf_brelse(bp); - return (error); + return error; } n = min(n, bsize - buf_resid(bp)); error = uiomove((char *)buf_dataptr(bp) + on, n, uio); if (error) { buf_brelse(bp); - return (error); + return error; } buf_markaged(bp); - if (io_sync) - error = buf_bwrite(bp); - else { - if ((n + on) == bsize) - error = buf_bawrite(bp); - else - error = buf_bdwrite(bp); + if (io_sync) { + error = buf_bwrite(bp); + } else { + if ((n + on) == bsize) { + error = buf_bawrite(bp); + } else { + error = buf_bdwrite(bp); + } } } while (error == 0 && uio_resid(uio) > 0 && n != 0); - return (error); + return error; default: panic("spec_write type"); } /* NOTREACHED */ - return (0); + return 0; } /* @@ -602,21 +775,22 @@ spec_ioctl(struct vnop_ioctl_args *ap) { proc_t p = vfs_context_proc(ap->a_context); dev_t dev = ap->a_vp->v_rdev; - int retval = 0; + int retval = 0; KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_IOCTL, 0) | DBG_FUNC_START, - (unsigned int)dev, (unsigned int)ap->a_command, (unsigned int)ap->a_fflag, (unsigned int)ap->a_vp->v_type, 0); + dev, ap->a_command, ap->a_fflag, ap->a_vp->v_type, 0); switch (ap->a_vp->v_type) { - case VCHR: retval = (*cdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, - ap->a_fflag, p); + ap->a_fflag, p); break; case VBLK: - retval = (*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, - ap->a_fflag, p); + retval = (*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, ap->a_fflag, p); + if (!retval && ap->a_command == DKIOCSETBLOCKSIZE) { + ap->a_vp->v_specsize = *(uint32_t *)ap->a_data; + } break; default: @@ -624,9 +798,9 @@ spec_ioctl(struct vnop_ioctl_args *ap) /* NOTREACHED */ } KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_IOCTL, 0) | DBG_FUNC_END, - (unsigned int)dev, (unsigned int)ap->a_command, (unsigned int)ap->a_fflag, retval, 0); + dev, ap->a_command, ap->a_fflag, retval, 0); - return (retval); + return retval; } int @@ -636,9 +810,8 @@ spec_select(struct vnop_select_args *ap) dev_t dev; switch (ap->a_vp->v_type) { - default: - return (1); /* XXX */ + return 1; /* XXX */ case VCHR: dev = ap->a_vp->v_rdev; @@ -646,29 +819,62 @@ spec_select(struct vnop_select_args *ap) } } -static int filt_specattach(struct knote *kn); +static int filt_specattach(struct knote *kn, struct kevent_qos_s *kev); int -spec_kqfilter(vnode_t vp, struct knote *kn) +spec_kqfilter(vnode_t vp, struct knote *kn, struct kevent_qos_s *kev) { dev_t dev; - int err = EINVAL; + assert(vnode_ischr(vp)); + + dev = vnode_specrdev(vp); + +#if NETWORKING /* - * For a few special kinds of devices, we can attach knotes. - * Each filter function must check whether the dev type matches it. + * Try a bpf device, as defined in bsd/net/bpf.c + * If it doesn't error out the attach, then it + * claimed it. Otherwise, fall through and try + * other attaches. */ - dev = vnode_specrdev(vp); + int32_t tmp_flags = kn->kn_flags; + int64_t tmp_sdata = kn->kn_sdata; + int res; - if (vnode_istty(vp)) { - /* We can hook into TTYs... */ - err = filt_specattach(kn); - } else { - /* Try a bpf device, as defined in bsd/net/bpf.c */ - err = bpfkqfilter(dev, kn); + res = bpfkqfilter(dev, kn); + if ((kn->kn_flags & EV_ERROR) == 0) { + return res; + } + kn->kn_flags = tmp_flags; + kn->kn_sdata = tmp_sdata; +#endif + + if (major(dev) > nchrdev) { + knote_set_error(kn, ENXIO); + return 0; + } + + kn->kn_vnode_kqok = !!(cdevsw_flags[major(dev)] & CDEVSW_SELECT_KQUEUE); + kn->kn_vnode_use_ofst = !!(cdevsw_flags[major(dev)] & CDEVSW_USE_OFFSET); + + if (cdevsw_flags[major(dev)] & CDEVSW_IS_PTS) { + kn->kn_filtid = EVFILTID_PTSD; + return ptsd_kqfilter(dev, kn); + } else if (cdevsw_flags[major(dev)] & CDEVSW_IS_PTC) { + kn->kn_filtid = EVFILTID_PTMX; + return ptmx_kqfilter(dev, kn); + } else if (cdevsw[major(dev)].d_type == D_TTY && kn->kn_vnode_kqok) { + /* + * TTYs from drivers that use struct ttys use their own filter + * routines. The PTC driver doesn't use the tty for character + * counts, so it must go through the select fallback. + */ + kn->kn_filtid = EVFILTID_TTY; + return knote_fops(kn)->f_attach(kn, kev); } - return err; + /* Try to attach to other char special devices */ + return filt_specattach(kn, kev); } /* @@ -677,14 +883,15 @@ spec_kqfilter(vnode_t vp, struct knote *kn) int spec_fsync_internal(vnode_t vp, int waitfor, __unused vfs_context_t context) { - if (vp->v_type == VCHR) - return (0); + if (vp->v_type == VCHR) { + return 0; + } /* * Flush all dirty buffers associated with a block device. */ buf_flushdirtyblks(vp, (waitfor == MNT_WAIT || waitfor == MNT_DWAIT), 0, "spec_fsync"); - return (0); + return 0; } int @@ -693,44 +900,44 @@ spec_fsync(struct vnop_fsync_args *ap) return spec_fsync_internal(ap->a_vp, ap->a_waitfor, ap->a_context); } + /* * Just call the device strategy routine */ -extern int hard_throttle_on_root; -void IOSleep(int); +void throttle_init(void); -// the low priority process may wait for at most LOWPRI_MAX_DELAY millisecond -#define LOWPRI_INITIAL_WINDOW_MSECS 100 -#define LOWPRI_WINDOW_MSECS_INC 50 -#define LOWPRI_MAX_WINDOW_MSECS 200 -#define LOWPRI_MAX_WAITING_MSECS 200 -#if CONFIG_EMBEDDED -#define LOWPRI_SLEEP_INTERVAL 5 +#if 0 +#define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) \ + do { \ + if ((debug_info)->alloc) \ + printf("%s: "format, __FUNCTION__, ## args); \ + } while(0) + #else -#define LOWPRI_SLEEP_INTERVAL 2 +#define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) #endif -int lowpri_IO_initial_window_msecs = LOWPRI_INITIAL_WINDOW_MSECS; -int lowpri_IO_window_msecs_inc = LOWPRI_WINDOW_MSECS_INC; -int lowpri_max_window_msecs = LOWPRI_MAX_WINDOW_MSECS; -int lowpri_max_waiting_msecs = LOWPRI_MAX_WAITING_MSECS; -#if 0 -#define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) \ - do { \ - if ((debug_info)->alloc) \ - printf("%s: "format, __FUNCTION__, ## args); \ - } while(0) +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier1_window_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_windows_msecs[THROTTLE_LEVEL_TIER1], 0, ""); +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier2_window_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_windows_msecs[THROTTLE_LEVEL_TIER2], 0, ""); +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier3_window_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_windows_msecs[THROTTLE_LEVEL_TIER3], 0, ""); -#else -#define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) -#endif +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier1_io_period_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_msecs[THROTTLE_LEVEL_TIER1], 0, ""); +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier2_io_period_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_msecs[THROTTLE_LEVEL_TIER2], 0, ""); +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier3_io_period_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_msecs[THROTTLE_LEVEL_TIER3], 0, ""); + +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier1_io_period_ssd_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_ssd_msecs[THROTTLE_LEVEL_TIER1], 0, ""); +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier2_io_period_ssd_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_ssd_msecs[THROTTLE_LEVEL_TIER2], 0, ""); +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier3_io_period_ssd_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_ssd_msecs[THROTTLE_LEVEL_TIER3], 0, ""); + +SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_enabled, CTLFLAG_RW | CTLFLAG_LOCKED, &lowpri_throttle_enabled, 0, ""); + + +static lck_grp_t *throttle_lock_grp; +static lck_attr_t *throttle_lock_attr; +static lck_grp_attr_t *throttle_lock_grp_attr; -SYSCTL_INT(_debug, OID_AUTO, lowpri_IO_initial_window_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &lowpri_IO_initial_window_msecs, LOWPRI_INITIAL_WINDOW_MSECS, ""); -SYSCTL_INT(_debug, OID_AUTO, lowpri_IO_window_inc, CTLFLAG_RW | CTLFLAG_LOCKED, &lowpri_IO_window_msecs_inc, LOWPRI_INITIAL_WINDOW_MSECS, ""); -SYSCTL_INT(_debug, OID_AUTO, lowpri_max_window_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &lowpri_max_window_msecs, LOWPRI_INITIAL_WINDOW_MSECS, ""); -SYSCTL_INT(_debug, OID_AUTO, lowpri_max_waiting_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &lowpri_max_waiting_msecs, LOWPRI_INITIAL_WINDOW_MSECS, ""); /* * throttled I/O helper function @@ -741,10 +948,11 @@ num_trailing_0(uint64_t n) { /* * since in most cases the number of trailing 0s is very small, - * we simply counting sequentially from the lowest bit + * we simply counting sequentially from the lowest bit */ - if (n == 0) + if (n == 0) { return sizeof(n) * 8; + } int count = 0; while (!ISSET(n, 1)) { n >>= 1; @@ -753,6 +961,7 @@ num_trailing_0(uint64_t n) return count; } + /* * Release the reference and if the item was allocated and this is the last * reference then free it. @@ -762,26 +971,30 @@ num_trailing_0(uint64_t n) static int throttle_info_rel(struct _throttle_io_info_t *info) { - SInt32 oldValue = OSDecrementAtomic(&info->refcnt); + SInt32 oldValue = OSDecrementAtomic(&info->throttle_refcnt); - DEBUG_ALLOC_THROTTLE_INFO("refcnt = %d info = %p\n", - info, (int)(oldValue -1), info ); + DEBUG_ALLOC_THROTTLE_INFO("refcnt = %d info = %p\n", + info, (int)(oldValue - 1), info ); /* The reference count just went negative, very bad */ - if (oldValue == 0) + if (oldValue == 0) { panic("throttle info ref cnt went negative!"); + } - /* - * Once reference count is zero, no one else should be able to take a - * reference + /* + * Once reference count is zero, no one else should be able to take a + * reference */ - if ((info->refcnt == 0) && (info->alloc)) { - DEBUG_ALLOC_THROTTLE_INFO("Freeing info = %p\n", info, info ); - FREE(info, M_TEMP); + if ((info->throttle_refcnt == 0) && (info->throttle_alloc)) { + DEBUG_ALLOC_THROTTLE_INFO("Freeing info = %p\n", info); + + lck_mtx_destroy(&info->throttle_lock, throttle_lock_grp); + FREE(info, M_TEMP); } return oldValue; } + /* * Just take a reference on the throttle info structure. * @@ -790,527 +1003,1595 @@ throttle_info_rel(struct _throttle_io_info_t *info) static SInt32 throttle_info_ref(struct _throttle_io_info_t *info) { - SInt32 oldValue = OSIncrementAtomic(&info->refcnt); + SInt32 oldValue = OSIncrementAtomic(&info->throttle_refcnt); - DEBUG_ALLOC_THROTTLE_INFO("refcnt = %d info = %p\n", - info, (int)(oldValue -1), info ); + DEBUG_ALLOC_THROTTLE_INFO("refcnt = %d info = %p\n", + info, (int)(oldValue - 1), info ); /* Allocated items should never have a reference of zero */ - if (info->alloc && (oldValue == 0)) + if (info->throttle_alloc && (oldValue == 0)) { panic("Taking a reference without calling create throttle info!\n"); + } return oldValue; } /* - * KPI routine - * - * Create and take a reference on a throttle info structure and return a - * pointer for the file system to use when calling throttle_info_update. - * Calling file system must have a matching release for every create. + * on entry the throttle_lock is held... + * this function is responsible for taking + * and dropping the reference on the info + * structure which will keep it from going + * away while the timer is running if it + * happens to have been dynamically allocated by + * a network fileystem kext which is now trying + * to free it */ -void * -throttle_info_create(void) +static uint32_t +throttle_timer_start(struct _throttle_io_info_t *info, boolean_t update_io_count, int wakelevel) { - struct _throttle_io_info_t *info; + struct timeval elapsed; + struct timeval now; + struct timeval period; + uint64_t elapsed_msecs; + int throttle_level; + int level; + int msecs; + boolean_t throttled = FALSE; + boolean_t need_timer = FALSE; + + microuptime(&now); + + if (update_io_count == TRUE) { + info->throttle_io_count_begin = info->throttle_io_count; + info->throttle_io_period_num++; + + while (wakelevel >= THROTTLE_LEVEL_THROTTLED) { + info->throttle_start_IO_period_timestamp[wakelevel--] = now; + } - MALLOC(info, struct _throttle_io_info_t *, sizeof(*info), M_TEMP, M_ZERO | M_WAITOK); - /* Should never happen but just in case */ - if (info == NULL) - return NULL; - /* Mark that this one was allocated and needs to be freed */ - DEBUG_ALLOC_THROTTLE_INFO("Creating info = %p\n", info, info ); - info->alloc = TRUE; - /* Take a reference */ - OSIncrementAtomic(&info->refcnt); - return info; -} + info->throttle_min_timer_deadline = now; -/* - * KPI routine - * - * Release the throttle info pointer if all the reference are gone. Should be - * called to release reference taken by throttle_info_create - */ -void -throttle_info_release(void *throttle_info) -{ - DEBUG_ALLOC_THROTTLE_INFO("Releaseing info = %p\n", - (struct _throttle_io_info_t *)throttle_info, - (struct _throttle_io_info_t *)throttle_info); - if (throttle_info) /* Just to be careful */ - throttle_info_rel(throttle_info); -} + msecs = info->throttle_io_periods[THROTTLE_LEVEL_THROTTLED]; + period.tv_sec = msecs / 1000; + period.tv_usec = (msecs % 1000) * 1000; -/* - * KPI routine - * - * File Systems that create an info structure, need to call this routine in - * their mount routine (used by cluster code). File Systems that call this in - * their mount routines must call throttle_info_mount_rel in their unmount - * routines. - */ -void -throttle_info_mount_ref(mount_t mp, void *throttle_info) -{ - if ((throttle_info == NULL) || (mp == NULL)) - return; - throttle_info_ref(throttle_info); - /* We already have a reference release it before adding the new one */ - if (mp->mnt_throttle_info) - throttle_info_rel(mp->mnt_throttle_info); - mp->mnt_throttle_info = throttle_info; -} + timevaladd(&info->throttle_min_timer_deadline, &period); + } + for (throttle_level = THROTTLE_LEVEL_START; throttle_level < THROTTLE_LEVEL_END; throttle_level++) { + elapsed = now; + timevalsub(&elapsed, &info->throttle_window_start_timestamp[throttle_level]); + elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000); + + for (level = throttle_level + 1; level <= THROTTLE_LEVEL_END; level++) { + if (!TAILQ_EMPTY(&info->throttle_uthlist[level])) { + if (elapsed_msecs < (uint64_t)throttle_windows_msecs[level] || info->throttle_inflight_count[throttle_level]) { + /* + * we had an I/O occur at a higher priority tier within + * this tier's throttle window + */ + throttled = TRUE; + } + /* + * we assume that the windows are the same or longer + * as we drop through the throttling tiers... thus + * we can stop looking once we run into a tier with + * threads to schedule regardless of whether it's + * still in its throttling window or not + */ + break; + } + } + if (throttled == TRUE) { + break; + } + } + if (throttled == TRUE) { + uint64_t deadline = 0; + struct timeval target; + struct timeval min_target; -/* - * Private KPI routine - * - * return a handle for accessing throttle_info given a throttle_mask. The - * handle must be released by throttle_info_rel_by_mask - */ -int -throttle_info_ref_by_mask(uint64_t throttle_mask, - throttle_info_handle_t *throttle_info_handle) -{ - int dev_index; - struct _throttle_io_info_t *info; + /* + * we've got at least one tier still in a throttled window + * so we need a timer running... compute the next deadline + * and schedule it + */ + for (level = throttle_level + 1; level <= THROTTLE_LEVEL_END; level++) { + if (TAILQ_EMPTY(&info->throttle_uthlist[level])) { + continue; + } - if (throttle_info_handle == NULL) - return EINVAL; - - dev_index = num_trailing_0(throttle_mask); - info = &_throttle_io_info[dev_index]; - throttle_info_ref(info); - *(struct _throttle_io_info_t**)throttle_info_handle = info; - return 0; -} + target = info->throttle_start_IO_period_timestamp[level]; -/* - * Private KPI routine - * - * release the handle obtained by throttle_info_ref_by_mask - */ -void -throttle_info_rel_by_mask(throttle_info_handle_t throttle_info_handle) -{ - /* for now the handle is just a pointer to _throttle_io_info_t */ - throttle_info_rel((struct _throttle_io_info_t*)throttle_info_handle); -} + msecs = info->throttle_io_periods[level]; + period.tv_sec = msecs / 1000; + period.tv_usec = (msecs % 1000) * 1000; -/* - * KPI routine - * - * File Systems that throttle_info_mount_ref, must call this routine in their - * umount routine. - */ -void -throttle_info_mount_rel(mount_t mp) -{ - if (mp->mnt_throttle_info) - throttle_info_rel(mp->mnt_throttle_info); - mp->mnt_throttle_info = NULL; -} + timevaladd(&target, &period); -void -throttle_info_get_last_io_time(mount_t mp, struct timeval *tv) -{ - struct _throttle_io_info_t *info; + if (need_timer == FALSE || timevalcmp(&target, &min_target, <)) { + min_target = target; + need_timer = TRUE; + } + } + if (timevalcmp(&info->throttle_min_timer_deadline, &now, >)) { + if (timevalcmp(&info->throttle_min_timer_deadline, &min_target, >)) { + min_target = info->throttle_min_timer_deadline; + } + } - if (mp == NULL) - info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; - else if (mp->mnt_throttle_info == NULL) - info = &_throttle_io_info[mp->mnt_devbsdunit]; - else - info = mp->mnt_throttle_info; + if (info->throttle_timer_active) { + if (thread_call_cancel(info->throttle_timer_call) == FALSE) { + /* + * couldn't kill the timer because it's already + * been dispatched, so don't try to start a new + * one... once we drop the lock, the timer will + * proceed and eventually re-run this function + */ + need_timer = FALSE; + } else { + info->throttle_timer_active = 0; + } + } + if (need_timer == TRUE) { + /* + * This is defined as an int (32-bit) rather than a 64-bit + * value because it would need a really big period in the + * order of ~500 days to overflow this. So, we let this be + * 32-bit which allows us to use the clock_interval_to_deadline() + * routine. + */ + int target_msecs; - *tv = info->last_IO_timestamp; -} + if (info->throttle_timer_ref == 0) { + /* + * take a reference for the timer + */ + throttle_info_ref(info); -void -update_last_io_time(mount_t mp) -{ - struct _throttle_io_info_t *info; - - if (mp == NULL) - info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; - else if (mp->mnt_throttle_info == NULL) - info = &_throttle_io_info[mp->mnt_devbsdunit]; - else - info = mp->mnt_throttle_info; + info->throttle_timer_ref = 1; + } + elapsed = min_target; + timevalsub(&elapsed, &now); + target_msecs = elapsed.tv_sec * 1000 + elapsed.tv_usec / 1000; - microuptime(&info->last_IO_timestamp); -} + if (target_msecs <= 0) { + /* + * we may have computed a deadline slightly in the past + * due to various factors... if so, just set the timer + * to go off in the near future (we don't need to be precise) + */ + target_msecs = 1; + } + clock_interval_to_deadline(target_msecs, 1000000, &deadline); + thread_call_enter_delayed(info->throttle_timer_call, deadline); + info->throttle_timer_active = 1; + } + } + return throttle_level; +} + + +static void +throttle_timer(struct _throttle_io_info_t *info) +{ + uthread_t ut, utlist; + struct timeval elapsed; + struct timeval now; + uint64_t elapsed_msecs; + int throttle_level; + int level; + int wake_level; + caddr_t wake_address = NULL; + boolean_t update_io_count = FALSE; + boolean_t need_wakeup = FALSE; + boolean_t need_release = FALSE; + + ut = NULL; + lck_mtx_lock(&info->throttle_lock); + + info->throttle_timer_active = 0; + microuptime(&now); + + elapsed = now; + timevalsub(&elapsed, &info->throttle_start_IO_period_timestamp[THROTTLE_LEVEL_THROTTLED]); + elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000); + + if (elapsed_msecs >= (uint64_t)info->throttle_io_periods[THROTTLE_LEVEL_THROTTLED]) { + wake_level = info->throttle_next_wake_level; + + for (level = THROTTLE_LEVEL_START; level < THROTTLE_LEVEL_END; level++) { + elapsed = now; + timevalsub(&elapsed, &info->throttle_start_IO_period_timestamp[wake_level]); + elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000); + + if (elapsed_msecs >= (uint64_t)info->throttle_io_periods[wake_level] && !TAILQ_EMPTY(&info->throttle_uthlist[wake_level])) { + /* + * we're closing out the current IO period... + * if we have a waiting thread, wake it up + * after we have reset the I/O window info + */ + need_wakeup = TRUE; + update_io_count = TRUE; + + info->throttle_next_wake_level = wake_level - 1; + + if (info->throttle_next_wake_level == THROTTLE_LEVEL_START) { + info->throttle_next_wake_level = THROTTLE_LEVEL_END; + } + + break; + } + wake_level--; + + if (wake_level == THROTTLE_LEVEL_START) { + wake_level = THROTTLE_LEVEL_END; + } + } + } + if (need_wakeup == TRUE) { + if (!TAILQ_EMPTY(&info->throttle_uthlist[wake_level])) { + ut = (uthread_t)TAILQ_FIRST(&info->throttle_uthlist[wake_level]); + TAILQ_REMOVE(&info->throttle_uthlist[wake_level], ut, uu_throttlelist); + ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE; + ut->uu_is_throttled = false; + + wake_address = (caddr_t)&ut->uu_on_throttlelist; + } + } else { + wake_level = THROTTLE_LEVEL_START; + } + + throttle_level = throttle_timer_start(info, update_io_count, wake_level); + + if (wake_address != NULL) { + wakeup(wake_address); + } + + for (level = THROTTLE_LEVEL_THROTTLED; level <= throttle_level; level++) { + TAILQ_FOREACH_SAFE(ut, &info->throttle_uthlist[level], uu_throttlelist, utlist) { + TAILQ_REMOVE(&info->throttle_uthlist[level], ut, uu_throttlelist); + ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE; + ut->uu_is_throttled = false; + + wakeup(&ut->uu_on_throttlelist); + } + } + if (info->throttle_timer_active == 0 && info->throttle_timer_ref) { + info->throttle_timer_ref = 0; + need_release = TRUE; + } + lck_mtx_unlock(&info->throttle_lock); + + if (need_release == TRUE) { + throttle_info_rel(info); + } +} + + +static int +throttle_add_to_list(struct _throttle_io_info_t *info, uthread_t ut, int mylevel, boolean_t insert_tail) +{ + boolean_t start_timer = FALSE; + int level = THROTTLE_LEVEL_START; + + if (TAILQ_EMPTY(&info->throttle_uthlist[mylevel])) { + info->throttle_start_IO_period_timestamp[mylevel] = info->throttle_last_IO_timestamp[mylevel]; + start_timer = TRUE; + } + + if (insert_tail == TRUE) { + TAILQ_INSERT_TAIL(&info->throttle_uthlist[mylevel], ut, uu_throttlelist); + } else { + TAILQ_INSERT_HEAD(&info->throttle_uthlist[mylevel], ut, uu_throttlelist); + } + + ut->uu_on_throttlelist = mylevel; + + if (start_timer == TRUE) { + /* we may need to start or rearm the timer */ + level = throttle_timer_start(info, FALSE, THROTTLE_LEVEL_START); + + if (level == THROTTLE_LEVEL_END) { + if (ut->uu_on_throttlelist >= THROTTLE_LEVEL_THROTTLED) { + TAILQ_REMOVE(&info->throttle_uthlist[ut->uu_on_throttlelist], ut, uu_throttlelist); + + ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE; + } + } + } + return level; +} + +static void +throttle_init_throttle_window(void) +{ + int throttle_window_size; + + /* + * The hierarchy of throttle window values is as follows: + * - Global defaults + * - Device tree properties + * - Boot-args + * All values are specified in msecs. + */ + + /* Override global values with device-tree properties */ + if (PE_get_default("kern.io_throttle_window_tier1", &throttle_window_size, sizeof(throttle_window_size))) { + throttle_windows_msecs[THROTTLE_LEVEL_TIER1] = throttle_window_size; + } + + if (PE_get_default("kern.io_throttle_window_tier2", &throttle_window_size, sizeof(throttle_window_size))) { + throttle_windows_msecs[THROTTLE_LEVEL_TIER2] = throttle_window_size; + } + + if (PE_get_default("kern.io_throttle_window_tier3", &throttle_window_size, sizeof(throttle_window_size))) { + throttle_windows_msecs[THROTTLE_LEVEL_TIER3] = throttle_window_size; + } + + /* Override with boot-args */ + if (PE_parse_boot_argn("io_throttle_window_tier1", &throttle_window_size, sizeof(throttle_window_size))) { + throttle_windows_msecs[THROTTLE_LEVEL_TIER1] = throttle_window_size; + } + + if (PE_parse_boot_argn("io_throttle_window_tier2", &throttle_window_size, sizeof(throttle_window_size))) { + throttle_windows_msecs[THROTTLE_LEVEL_TIER2] = throttle_window_size; + } + + if (PE_parse_boot_argn("io_throttle_window_tier3", &throttle_window_size, sizeof(throttle_window_size))) { + throttle_windows_msecs[THROTTLE_LEVEL_TIER3] = throttle_window_size; + } +} + +static void +throttle_init_throttle_period(struct _throttle_io_info_t *info, boolean_t isssd) +{ + int throttle_period_size; + + /* + * The hierarchy of throttle period values is as follows: + * - Global defaults + * - Device tree properties + * - Boot-args + * All values are specified in msecs. + */ + + /* Assign global defaults */ + if ((isssd == TRUE) && (info->throttle_is_fusion_with_priority == 0)) { + info->throttle_io_periods = &throttle_io_period_ssd_msecs[0]; + } else { + info->throttle_io_periods = &throttle_io_period_msecs[0]; + } + + /* Override global values with device-tree properties */ + if (PE_get_default("kern.io_throttle_period_tier1", &throttle_period_size, sizeof(throttle_period_size))) { + info->throttle_io_periods[THROTTLE_LEVEL_TIER1] = throttle_period_size; + } + + if (PE_get_default("kern.io_throttle_period_tier2", &throttle_period_size, sizeof(throttle_period_size))) { + info->throttle_io_periods[THROTTLE_LEVEL_TIER2] = throttle_period_size; + } + + if (PE_get_default("kern.io_throttle_period_tier3", &throttle_period_size, sizeof(throttle_period_size))) { + info->throttle_io_periods[THROTTLE_LEVEL_TIER3] = throttle_period_size; + } + + /* Override with boot-args */ + if (PE_parse_boot_argn("io_throttle_period_tier1", &throttle_period_size, sizeof(throttle_period_size))) { + info->throttle_io_periods[THROTTLE_LEVEL_TIER1] = throttle_period_size; + } + + if (PE_parse_boot_argn("io_throttle_period_tier2", &throttle_period_size, sizeof(throttle_period_size))) { + info->throttle_io_periods[THROTTLE_LEVEL_TIER2] = throttle_period_size; + } -#if CONFIG_EMBEDDED + if (PE_parse_boot_argn("io_throttle_period_tier3", &throttle_period_size, sizeof(throttle_period_size))) { + info->throttle_io_periods[THROTTLE_LEVEL_TIER3] = throttle_period_size; + } +} + +#if CONFIG_IOSCHED +extern void vm_io_reprioritize_init(void); +int iosched_enabled = 1; +#endif + +void +throttle_init(void) +{ + struct _throttle_io_info_t *info; + int i; + int level; +#if CONFIG_IOSCHED + int iosched; +#endif + /* + * allocate lock group attribute and group + */ + throttle_lock_grp_attr = lck_grp_attr_alloc_init(); + throttle_lock_grp = lck_grp_alloc_init("throttle I/O", throttle_lock_grp_attr); + + /* Update throttle parameters based on device tree configuration */ + throttle_init_throttle_window(); + + /* + * allocate the lock attribute + */ + throttle_lock_attr = lck_attr_alloc_init(); + + for (i = 0; i < LOWPRI_MAX_NUM_DEV; i++) { + info = &_throttle_io_info[i]; + + lck_mtx_init(&info->throttle_lock, throttle_lock_grp, throttle_lock_attr); + info->throttle_timer_call = thread_call_allocate((thread_call_func_t)throttle_timer, (thread_call_param_t)info); + + for (level = 0; level <= THROTTLE_LEVEL_END; level++) { + TAILQ_INIT(&info->throttle_uthlist[level]); + info->throttle_last_IO_pid[level] = 0; + info->throttle_inflight_count[level] = 0; + } + info->throttle_next_wake_level = THROTTLE_LEVEL_END; + info->throttle_disabled = 0; + info->throttle_is_fusion_with_priority = 0; + } +#if CONFIG_IOSCHED + if (PE_parse_boot_argn("iosched", &iosched, sizeof(iosched))) { + iosched_enabled = iosched; + } + if (iosched_enabled) { + /* Initialize I/O Reprioritization mechanism */ + vm_io_reprioritize_init(); + } +#endif +} + +void +sys_override_io_throttle(boolean_t enable_override) +{ + if (enable_override) { + lowpri_throttle_enabled = 0; + } else { + lowpri_throttle_enabled = 1; + } +} + +int rethrottle_wakeups = 0; + +/* + * the uu_rethrottle_lock is used to synchronize this function + * with "throttle_lowpri_io" which is where a throttled thread + * will block... that function will grab this lock before beginning + * it's decision making process concerning the need to block, and + * hold it through the assert_wait. When that thread is awakened + * for any reason (timer or rethrottle), it will reacquire the + * uu_rethrottle_lock before determining if it really is ok for + * it to now run. This is the point at which the thread could + * enter a different throttling queue and reblock or return from + * the throttle w/o having waited out it's entire throttle if + * the rethrottle has now moved it out of any currently + * active throttle window. + * + * + * NOTES: + * 1 - This may be called with the task lock held. + * 2 - This may be called with preemption and interrupts disabled + * in the kqueue wakeup path so we can't take the throttle_lock which is a mutex + * 3 - This cannot safely dereference uu_throttle_info, as it may + * get deallocated out from under us + */ + +void +rethrottle_thread(uthread_t ut) +{ + /* + * If uthread doesn't have throttle state, then there's no chance + * of it needing a rethrottle. + */ + if (ut->uu_throttle_info == NULL) { + return; + } + + boolean_t s = ml_set_interrupts_enabled(FALSE); + lck_spin_lock(&ut->uu_rethrottle_lock); -int throttle_get_io_policy(struct uthread **ut) + if (!ut->uu_is_throttled) { + ut->uu_was_rethrottled = true; + } else { + int my_new_level = throttle_get_thread_throttle_level(ut); + + if (my_new_level != ut->uu_on_throttlelist) { + /* + * ut is currently blocked (as indicated by + * ut->uu_is_throttled == true) + * and we're changing it's throttle level, so + * we need to wake it up. + */ + ut->uu_is_throttled = false; + wakeup(&ut->uu_on_throttlelist); + + rethrottle_wakeups++; + KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 102)), thread_tid(ut->uu_thread), ut->uu_on_throttlelist, my_new_level, 0, 0); + } + } + lck_spin_unlock(&ut->uu_rethrottle_lock); + ml_set_interrupts_enabled(s); +} + + +/* + * KPI routine + * + * Create and take a reference on a throttle info structure and return a + * pointer for the file system to use when calling throttle_info_update. + * Calling file system must have a matching release for every create. + */ +void * +throttle_info_create(void) +{ + struct _throttle_io_info_t *info; + int level; + + MALLOC(info, struct _throttle_io_info_t *, sizeof(*info), M_TEMP, M_ZERO | M_WAITOK); + /* Should never happen but just in case */ + if (info == NULL) { + return NULL; + } + /* Mark that this one was allocated and needs to be freed */ + DEBUG_ALLOC_THROTTLE_INFO("Creating info = %p\n", info, info ); + info->throttle_alloc = TRUE; + + lck_mtx_init(&info->throttle_lock, throttle_lock_grp, throttle_lock_attr); + info->throttle_timer_call = thread_call_allocate((thread_call_func_t)throttle_timer, (thread_call_param_t)info); + + for (level = 0; level <= THROTTLE_LEVEL_END; level++) { + TAILQ_INIT(&info->throttle_uthlist[level]); + } + info->throttle_next_wake_level = THROTTLE_LEVEL_END; + + /* Take a reference */ + OSIncrementAtomic(&info->throttle_refcnt); + return info; +} + +/* + * KPI routine + * + * Release the throttle info pointer if all the reference are gone. Should be + * called to release reference taken by throttle_info_create + */ +void +throttle_info_release(void *throttle_info) +{ + DEBUG_ALLOC_THROTTLE_INFO("Releaseing info = %p\n", + (struct _throttle_io_info_t *)throttle_info, + (struct _throttle_io_info_t *)throttle_info); + if (throttle_info) { /* Just to be careful */ + throttle_info_rel(throttle_info); + } +} + +/* + * KPI routine + * + * File Systems that create an info structure, need to call this routine in + * their mount routine (used by cluster code). File Systems that call this in + * their mount routines must call throttle_info_mount_rel in their unmount + * routines. + */ +void +throttle_info_mount_ref(mount_t mp, void *throttle_info) +{ + if ((throttle_info == NULL) || (mp == NULL)) { + return; + } + throttle_info_ref(throttle_info); + + /* + * We already have a reference release it before adding the new one + */ + if (mp->mnt_throttle_info) { + throttle_info_rel(mp->mnt_throttle_info); + } + mp->mnt_throttle_info = throttle_info; +} + +/* + * Private KPI routine + * + * return a handle for accessing throttle_info given a throttle_mask. The + * handle must be released by throttle_info_rel_by_mask + */ +int +throttle_info_ref_by_mask(uint64_t throttle_mask, throttle_info_handle_t *throttle_info_handle) +{ + int dev_index; + struct _throttle_io_info_t *info; + + if (throttle_info_handle == NULL) { + return EINVAL; + } + + dev_index = num_trailing_0(throttle_mask); + info = &_throttle_io_info[dev_index]; + throttle_info_ref(info); + *(struct _throttle_io_info_t**)throttle_info_handle = info; + + return 0; +} + +/* + * Private KPI routine + * + * release the handle obtained by throttle_info_ref_by_mask + */ +void +throttle_info_rel_by_mask(throttle_info_handle_t throttle_info_handle) +{ + /* + * for now the handle is just a pointer to _throttle_io_info_t + */ + throttle_info_rel((struct _throttle_io_info_t*)throttle_info_handle); +} + +/* + * KPI routine + * + * File Systems that throttle_info_mount_ref, must call this routine in their + * umount routine. + */ +void +throttle_info_mount_rel(mount_t mp) +{ + if (mp->mnt_throttle_info) { + throttle_info_rel(mp->mnt_throttle_info); + } + mp->mnt_throttle_info = NULL; +} + +/* + * Reset throttling periods for the given mount point + * + * private interface used by disk conditioner to reset + * throttling periods when 'is_ssd' status changes + */ +void +throttle_info_mount_reset_period(mount_t mp, int isssd) +{ + struct _throttle_io_info_t *info; + + if (mp == NULL) { + info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; + } else if (mp->mnt_throttle_info == NULL) { + info = &_throttle_io_info[mp->mnt_devbsdunit]; + } else { + info = mp->mnt_throttle_info; + } + + throttle_init_throttle_period(info, isssd); +} + +void +throttle_info_get_last_io_time(mount_t mp, struct timeval *tv) +{ + struct _throttle_io_info_t *info; + + if (mp == NULL) { + info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; + } else if (mp->mnt_throttle_info == NULL) { + info = &_throttle_io_info[mp->mnt_devbsdunit]; + } else { + info = mp->mnt_throttle_info; + } + + *tv = info->throttle_last_write_timestamp; +} + +void +update_last_io_time(mount_t mp) +{ + struct _throttle_io_info_t *info; + + if (mp == NULL) { + info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; + } else if (mp->mnt_throttle_info == NULL) { + info = &_throttle_io_info[mp->mnt_devbsdunit]; + } else { + info = mp->mnt_throttle_info; + } + + microuptime(&info->throttle_last_write_timestamp); + if (mp != NULL) { + mp->mnt_last_write_completed_timestamp = info->throttle_last_write_timestamp; + } +} + +int +throttle_get_io_policy(uthread_t *ut) +{ + if (ut != NULL) { + *ut = get_bsdthread_info(current_thread()); + } + + return proc_get_effective_thread_policy(current_thread(), TASK_POLICY_IO); +} + +int +throttle_get_passive_io_policy(uthread_t *ut) +{ + if (ut != NULL) { + *ut = get_bsdthread_info(current_thread()); + } + + return proc_get_effective_thread_policy(current_thread(), TASK_POLICY_PASSIVE_IO); +} + + +static int +throttle_get_thread_throttle_level(uthread_t ut) +{ + uthread_t *ut_p = (ut == NULL) ? &ut : NULL; + int io_tier = throttle_get_io_policy(ut_p); + + return throttle_get_thread_throttle_level_internal(ut, io_tier); +} + +/* + * Return a throttle level given an existing I/O tier (such as returned by throttle_get_io_policy) + */ +static int +throttle_get_thread_throttle_level_internal(uthread_t ut, int io_tier) +{ + int thread_throttle_level = io_tier; + int user_idle_level; + + assert(ut != NULL); + + /* Bootcache misses should always be throttled */ + if (ut->uu_throttle_bc) { + thread_throttle_level = THROTTLE_LEVEL_TIER3; + } + + /* + * Issue tier3 I/O as tier2 when the user is idle + * to allow maintenance tasks to make more progress. + * + * Assume any positive idle level is enough... for now it's + * only ever 0 or 128 but this is not defined anywhere. + */ + if (thread_throttle_level >= THROTTLE_LEVEL_TIER3) { + user_idle_level = timer_get_user_idle_level(); + if (user_idle_level > 0) { + thread_throttle_level--; + } + } + + return thread_throttle_level; +} + +/* + * I/O will be throttled if either of the following are true: + * - Higher tiers have in-flight I/O + * - The time delta since the last start/completion of a higher tier is within the throttle window interval + * + * In-flight I/O is bookended by throttle_info_update_internal/throttle_info_end_io_internal + */ +static int +throttle_io_will_be_throttled_internal(void * throttle_info, int * mylevel, int * throttling_level) +{ + struct _throttle_io_info_t *info = throttle_info; + struct timeval elapsed; + struct timeval now; + uint64_t elapsed_msecs; + int thread_throttle_level; + int throttle_level; + + if ((thread_throttle_level = throttle_get_thread_throttle_level(NULL)) < THROTTLE_LEVEL_THROTTLED) { + return THROTTLE_DISENGAGED; + } + + microuptime(&now); + + for (throttle_level = THROTTLE_LEVEL_START; throttle_level < thread_throttle_level; throttle_level++) { + if (info->throttle_inflight_count[throttle_level]) { + break; + } + elapsed = now; + timevalsub(&elapsed, &info->throttle_window_start_timestamp[throttle_level]); + elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000); + + if (elapsed_msecs < (uint64_t)throttle_windows_msecs[thread_throttle_level]) { + break; + } + } + if (throttle_level >= thread_throttle_level) { + /* + * we're beyond all of the throttle windows + * that affect the throttle level of this thread, + * so go ahead and treat as normal I/O + */ + return THROTTLE_DISENGAGED; + } + if (mylevel) { + *mylevel = thread_throttle_level; + } + if (throttling_level) { + *throttling_level = throttle_level; + } + + if (info->throttle_io_count != info->throttle_io_count_begin) { + /* + * we've already issued at least one throttleable I/O + * in the current I/O window, so avoid issuing another one + */ + return THROTTLE_NOW; + } + /* + * we're in the throttle window, so + * cut the I/O size back + */ + return THROTTLE_ENGAGED; +} + +/* + * If we have a mount point and it has a throttle info pointer then + * use it to do the check, otherwise use the device unit number to find + * the correct throttle info array element. + */ +int +throttle_io_will_be_throttled(__unused int lowpri_window_msecs, mount_t mp) { - int policy = IOPOL_DEFAULT; - proc_t p = current_proc(); + struct _throttle_io_info_t *info; - *ut = get_bsdthread_info(current_thread()); - - if (p != NULL) - policy = p->p_iopol_disk; - - if (*ut != NULL) { - // the I/O policy of the thread overrides that of the process - // unless the I/O policy of the thread is default - if ((*ut)->uu_iopol_disk != IOPOL_DEFAULT) - policy = (*ut)->uu_iopol_disk; + /* + * Should we just return zero if no mount point + */ + if (mp == NULL) { + info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; + } else if (mp->mnt_throttle_info == NULL) { + info = &_throttle_io_info[mp->mnt_devbsdunit]; + } else { + info = mp->mnt_throttle_info; } - return policy; -} -#else -int throttle_get_io_policy(__unused struct uthread **ut) -{ - *ut = get_bsdthread_info(current_thread()); + if (info->throttle_is_fusion_with_priority) { + uthread_t ut = get_bsdthread_info(current_thread()); + if (ut->uu_lowpri_window == 0) { + return THROTTLE_DISENGAGED; + } + } - return (proc_get_task_selfdiskacc()); + if (info->throttle_disabled) { + return THROTTLE_DISENGAGED; + } else { + return throttle_io_will_be_throttled_internal(info, NULL, NULL); + } } -#endif +/* + * Routine to increment I/O throttling counters maintained in the proc + */ -static int -throttle_io_will_be_throttled_internal(int lowpri_window_msecs, void * throttle_info) +static void +throttle_update_proc_stats(pid_t throttling_pid, int count) { - struct _throttle_io_info_t *info = throttle_info; - struct timeval elapsed; - int elapsed_msecs; - int policy; - struct uthread *ut; - - policy = throttle_get_io_policy(&ut); - - if (ut->uu_throttle_bc == FALSE && policy != IOPOL_THROTTLE) - return (0); - - microuptime(&elapsed); - timevalsub(&elapsed, &info->last_normal_IO_timestamp); - elapsed_msecs = elapsed.tv_sec * 1000 + elapsed.tv_usec / 1000; + proc_t throttling_proc; + proc_t throttled_proc = current_proc(); - if (lowpri_window_msecs == -1) // use the max waiting time - lowpri_window_msecs = lowpri_max_waiting_msecs; + /* The throttled_proc is always the current proc; so we are not concerned with refs */ + OSAddAtomic64(count, &(throttled_proc->was_throttled)); - return elapsed_msecs < lowpri_window_msecs; + /* The throttling pid might have exited by now */ + throttling_proc = proc_find(throttling_pid); + if (throttling_proc != PROC_NULL) { + OSAddAtomic64(count, &(throttling_proc->did_throttle)); + proc_rele(throttling_proc); + } } -/* - * If we have a mount point and it has a throttle info pointer then - * use it to do the check, otherwise use the device unit number to find - * the correct throttle info array element. +/* + * Block until woken up by the throttle timer or by a rethrottle call. + * As long as we hold the throttle_lock while querying the throttle tier, we're + * safe against seeing an old throttle tier after a rethrottle. */ -int -throttle_io_will_be_throttled(int lowpri_window_msecs, mount_t mp) -{ - void *info; - - /* Should we just return zero if no mount point */ - if (mp == NULL) - info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; - else if (mp->mnt_throttle_info == NULL) - info = &_throttle_io_info[mp->mnt_devbsdunit]; - else - info = mp->mnt_throttle_info; - return throttle_io_will_be_throttled_internal(lowpri_window_msecs, info); -} - uint32_t throttle_lowpri_io(int sleep_amount) { - int sleep_cnt = 0; - int numthreads_throttling; - int max_try_num; - struct uthread *ut; + uthread_t ut; struct _throttle_io_info_t *info; - int max_waiting_msecs; + int throttle_type = 0; + int mylevel = 0; + int throttling_level = THROTTLE_LEVEL_NONE; + int sleep_cnt = 0; + uint32_t throttle_io_period_num = 0; + boolean_t insert_tail = TRUE; + boolean_t s; ut = get_bsdthread_info(current_thread()); - if ((ut->uu_lowpri_window == 0) || (ut->uu_throttle_info == NULL)) - goto done; + if (ut->uu_lowpri_window == 0) { + return 0; + } info = ut->uu_throttle_info; - if (sleep_amount != 0) { -#if CONFIG_EMBEDDED - max_waiting_msecs = lowpri_max_waiting_msecs; -#else - if (ut->uu_throttle_isssd == TRUE) - max_waiting_msecs = lowpri_max_waiting_msecs / 100; - else - max_waiting_msecs = lowpri_max_waiting_msecs; -#endif - if (max_waiting_msecs < LOWPRI_SLEEP_INTERVAL) - max_waiting_msecs = LOWPRI_SLEEP_INTERVAL; + if (info == NULL) { + ut->uu_throttle_bc = false; + ut->uu_lowpri_window = 0; + return 0; + } + lck_mtx_lock(&info->throttle_lock); + assert(ut->uu_on_throttlelist < THROTTLE_LEVEL_THROTTLED); - numthreads_throttling = info->numthreads_throttling + MIN(10, MAX(1, sleep_amount)) - 1; - max_try_num = max_waiting_msecs / LOWPRI_SLEEP_INTERVAL * MAX(1, numthreads_throttling); + if (sleep_amount == 0) { + goto done; + } - for (sleep_cnt = 0; sleep_cnt < max_try_num; sleep_cnt++) { - if (throttle_io_will_be_throttled_internal(ut->uu_lowpri_window, info)) { - if (sleep_cnt == 0) { - KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 97)) | DBG_FUNC_START, - ut->uu_lowpri_window, max_try_num, numthreads_throttling, 0, 0); - } - IOSleep(LOWPRI_SLEEP_INTERVAL); - DEBUG_ALLOC_THROTTLE_INFO("sleeping because of info = %p\n", info, info ); - } else { + if (sleep_amount == 1 && !ut->uu_throttle_bc) { + sleep_amount = 0; + } + + throttle_io_period_num = info->throttle_io_period_num; + + ut->uu_was_rethrottled = false; + + while ((throttle_type = throttle_io_will_be_throttled_internal(info, &mylevel, &throttling_level))) { + if (throttle_type == THROTTLE_ENGAGED) { + if (sleep_amount == 0) { + break; + } + if (info->throttle_io_period_num < throttle_io_period_num) { + break; + } + if ((info->throttle_io_period_num - throttle_io_period_num) >= (uint32_t)sleep_amount) { break; } } - if (sleep_cnt) { - KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 97)) | DBG_FUNC_END, - ut->uu_lowpri_window, sleep_cnt, 0, 0, 0); + /* + * keep the same position in the list if "rethrottle_thread" changes our throttle level and + * then puts us back to the original level before we get a chance to run + */ + if (ut->uu_on_throttlelist >= THROTTLE_LEVEL_THROTTLED && ut->uu_on_throttlelist != mylevel) { + /* + * must have been awakened via "rethrottle_thread" (the timer pulls us off the list) + * and we've changed our throttling level, so pull ourselves off of the appropriate list + * and make sure we get put on the tail of the new list since we're starting anew w/r to + * the throttling engine + */ + TAILQ_REMOVE(&info->throttle_uthlist[ut->uu_on_throttlelist], ut, uu_throttlelist); + ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE; + insert_tail = TRUE; + } + if (ut->uu_on_throttlelist < THROTTLE_LEVEL_THROTTLED) { + if (throttle_add_to_list(info, ut, mylevel, insert_tail) == THROTTLE_LEVEL_END) { + goto done; + } } - } - SInt32 oldValue; - oldValue = OSDecrementAtomic(&info->numthreads_throttling); + assert(throttling_level >= THROTTLE_LEVEL_START && throttling_level <= THROTTLE_LEVEL_END); + + s = ml_set_interrupts_enabled(FALSE); + lck_spin_lock(&ut->uu_rethrottle_lock); + + /* + * this is the critical section w/r to our interaction + * with "rethrottle_thread" + */ + if (ut->uu_was_rethrottled) { + lck_spin_unlock(&ut->uu_rethrottle_lock); + ml_set_interrupts_enabled(s); + lck_mtx_yield(&info->throttle_lock); + + KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 103)), thread_tid(ut->uu_thread), ut->uu_on_throttlelist, 0, 0, 0); + + ut->uu_was_rethrottled = false; + continue; + } + KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_THROTTLE, PROCESS_THROTTLED)) | DBG_FUNC_NONE, + info->throttle_last_IO_pid[throttling_level], throttling_level, proc_selfpid(), mylevel, 0); + + if (sleep_cnt == 0) { + KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 97)) | DBG_FUNC_START, + throttle_windows_msecs[mylevel], info->throttle_io_periods[mylevel], info->throttle_io_count, 0, 0); + throttled_count[mylevel]++; + } + ut->uu_wmesg = "throttle_lowpri_io"; + + assert_wait((caddr_t)&ut->uu_on_throttlelist, THREAD_UNINT); + + ut->uu_is_throttled = true; + lck_spin_unlock(&ut->uu_rethrottle_lock); + ml_set_interrupts_enabled(s); + + lck_mtx_unlock(&info->throttle_lock); + + thread_block(THREAD_CONTINUE_NULL); + + ut->uu_wmesg = NULL; + + ut->uu_is_throttled = false; + ut->uu_was_rethrottled = false; + + lck_mtx_lock(&info->throttle_lock); - if (oldValue <= 0) { - panic("%s: numthreads negative", __func__); + sleep_cnt++; + + if (sleep_amount == 0) { + insert_tail = FALSE; + } else if (info->throttle_io_period_num < throttle_io_period_num || + (info->throttle_io_period_num - throttle_io_period_num) >= (uint32_t)sleep_amount) { + insert_tail = FALSE; + sleep_amount = 0; + } } done: - ut->uu_lowpri_window = 0; - if (ut->uu_throttle_info) - throttle_info_rel(ut->uu_throttle_info); + if (ut->uu_on_throttlelist >= THROTTLE_LEVEL_THROTTLED) { + TAILQ_REMOVE(&info->throttle_uthlist[ut->uu_on_throttlelist], ut, uu_throttlelist); + ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE; + } + lck_mtx_unlock(&info->throttle_lock); + + if (sleep_cnt) { + KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 97)) | DBG_FUNC_END, + throttle_windows_msecs[mylevel], info->throttle_io_periods[mylevel], info->throttle_io_count, 0, 0); + /* + * We update the stats for the last pid which opened a throttle window for the throttled thread. + * This might not be completely accurate since the multiple throttles seen by the lower tier pid + * might have been caused by various higher prio pids. However, updating these stats accurately + * means doing a proc_find while holding the throttle lock which leads to deadlock. + */ + throttle_update_proc_stats(info->throttle_last_IO_pid[throttling_level], sleep_cnt); + } + ut->uu_throttle_info = NULL; - ut->uu_throttle_bc = FALSE; + ut->uu_throttle_bc = false; + ut->uu_lowpri_window = 0; + + throttle_info_rel(info); + + return sleep_cnt; +} + +/* + * returns TRUE if the throttle_lowpri_io called with the same sleep_amount would've slept + * This function mimics the most of the throttle_lowpri_io checks but without actual sleeping + */ +int +throttle_lowpri_io_will_be_throttled(int sleep_amount) +{ + if (sleep_amount == 0) { + return FALSE; + } + + uthread_t ut = get_bsdthread_info(current_thread()); + if (ut->uu_lowpri_window == 0) { + return FALSE; + } + + struct _throttle_io_info_t *info = ut->uu_throttle_info; + if (info == NULL) { + return FALSE; + } - return (sleep_cnt * LOWPRI_SLEEP_INTERVAL); + lck_mtx_lock(&info->throttle_lock); + assert(ut->uu_on_throttlelist < THROTTLE_LEVEL_THROTTLED); + + if (sleep_amount == 1 && !ut->uu_throttle_bc) { + sleep_amount = 0; + } + + int result = FALSE; + + int throttle_type = throttle_io_will_be_throttled_internal(info, NULL, NULL); + if (throttle_type > THROTTLE_DISENGAGED) { + result = TRUE; + if ((throttle_type == THROTTLE_ENGAGED) && (sleep_amount == 0)) { + result = FALSE; + } + } + + lck_mtx_unlock(&info->throttle_lock); + + return result; } + /* * KPI routine * * set a kernel thread's IO policy. policy can be: - * IOPOL_NORMAL, IOPOL_THROTTLE, IOPOL_PASSIVE + * IOPOL_NORMAL, IOPOL_THROTTLE, IOPOL_PASSIVE, IOPOL_UTILITY, IOPOL_STANDARD * * explanations about these policies are in the man page of setiopolicy_np */ -void throttle_set_thread_io_policy(int policy) +void +throttle_set_thread_io_policy(int policy) { -#if !CONFIG_EMBEDDED - proc_apply_thread_selfdiskacc(policy); -#else /* !CONFIG_EMBEDDED */ - struct uthread *ut; - ut = get_bsdthread_info(current_thread()); - ut->uu_iopol_disk = policy; -#endif /* !CONFIG_EMBEDDED */ + proc_set_thread_policy(current_thread(), TASK_POLICY_INTERNAL, TASK_POLICY_IOPOL, policy); } +int +throttle_get_thread_effective_io_policy() +{ + return proc_get_effective_thread_policy(current_thread(), TASK_POLICY_IO); +} -static -void throttle_info_reset_window(struct uthread *ut) +void +throttle_info_reset_window(uthread_t ut) { struct _throttle_io_info_t *info; - info = ut->uu_throttle_info; + if (ut == NULL) { + ut = get_bsdthread_info(current_thread()); + } - OSDecrementAtomic(&info->numthreads_throttling); - throttle_info_rel(info); - ut->uu_throttle_info = NULL; - ut->uu_lowpri_window = 0; + if ((info = ut->uu_throttle_info)) { + throttle_info_rel(info); + + ut->uu_throttle_info = NULL; + ut->uu_lowpri_window = 0; + ut->uu_throttle_bc = false; + } } static -void throttle_info_set_initial_window(struct uthread *ut, struct _throttle_io_info_t *info, boolean_t isssd, boolean_t BC_throttle) +void +throttle_info_set_initial_window(uthread_t ut, struct _throttle_io_info_t *info, boolean_t BC_throttle, boolean_t isssd) { - SInt32 oldValue; + if (lowpri_throttle_enabled == 0 || info->throttle_disabled) { + return; + } - ut->uu_throttle_info = info; - throttle_info_ref(info); - DEBUG_ALLOC_THROTTLE_INFO("updating info = %p\n", info, info ); + if (info->throttle_io_periods == 0) { + throttle_init_throttle_period(info, isssd); + } + if (ut->uu_throttle_info == NULL) { + ut->uu_throttle_info = info; + throttle_info_ref(info); + DEBUG_ALLOC_THROTTLE_INFO("updating info = %p\n", info, info ); + + ut->uu_lowpri_window = 1; + ut->uu_throttle_bc = BC_throttle; + } +} + +/* + * Update inflight IO count and throttling window + * Should be called when an IO is done + * + * Only affects IO that was sent through spec_strategy + */ +void +throttle_info_end_io(buf_t bp) +{ + mount_t mp; + struct bufattr *bap; + struct _throttle_io_info_t *info; + int io_tier; + + bap = &bp->b_attr; + if (!ISSET(bap->ba_flags, BA_STRATEGY_TRACKED_IO)) { + return; + } + CLR(bap->ba_flags, BA_STRATEGY_TRACKED_IO); + + mp = buf_vnode(bp)->v_mount; + if (mp != NULL) { + info = &_throttle_io_info[mp->mnt_devbsdunit]; + } else { + info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; + } - oldValue = OSIncrementAtomic(&info->numthreads_throttling); - if (oldValue < 0) { - panic("%s: numthreads negative", __func__); + io_tier = GET_BUFATTR_IO_TIER(bap); + if (ISSET(bap->ba_flags, BA_IO_TIER_UPGRADE)) { + io_tier--; } - ut->uu_lowpri_window = lowpri_IO_initial_window_msecs; - ut->uu_lowpri_window += lowpri_IO_window_msecs_inc * oldValue; - ut->uu_throttle_isssd = isssd; - ut->uu_throttle_bc = BC_throttle; + + throttle_info_end_io_internal(info, io_tier); } +/* + * Decrement inflight count initially incremented by throttle_info_update_internal + */ +static +void +throttle_info_end_io_internal(struct _throttle_io_info_t *info, int throttle_level) +{ + if (throttle_level == THROTTLE_LEVEL_NONE) { + return; + } + + microuptime(&info->throttle_window_start_timestamp[throttle_level]); + OSDecrementAtomic(&info->throttle_inflight_count[throttle_level]); + assert(info->throttle_inflight_count[throttle_level] >= 0); +} +/* + * If inflight is TRUE and bap is NULL then the caller is responsible for calling + * throttle_info_end_io_internal to avoid leaking in-flight I/O. + */ static -void throttle_info_update_internal(void *throttle_info, int flags, boolean_t isssd) +int +throttle_info_update_internal(struct _throttle_io_info_t *info, uthread_t ut, int flags, boolean_t isssd, boolean_t inflight, struct bufattr *bap) +{ + int thread_throttle_level; + + if (lowpri_throttle_enabled == 0 || info->throttle_disabled) { + return THROTTLE_LEVEL_NONE; + } + + if (ut == NULL) { + ut = get_bsdthread_info(current_thread()); + } + + if (bap && inflight && !ut->uu_throttle_bc) { + thread_throttle_level = GET_BUFATTR_IO_TIER(bap); + if (ISSET(bap->ba_flags, BA_IO_TIER_UPGRADE)) { + thread_throttle_level--; + } + } else { + thread_throttle_level = throttle_get_thread_throttle_level(ut); + } + + if (thread_throttle_level != THROTTLE_LEVEL_NONE) { + if (!ISSET(flags, B_PASSIVE)) { + info->throttle_last_IO_pid[thread_throttle_level] = proc_selfpid(); + if (inflight && !ut->uu_throttle_bc) { + if (NULL != bap) { + SET(bap->ba_flags, BA_STRATEGY_TRACKED_IO); + } + OSIncrementAtomic(&info->throttle_inflight_count[thread_throttle_level]); + } else { + microuptime(&info->throttle_window_start_timestamp[thread_throttle_level]); + } + KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_THROTTLE, OPEN_THROTTLE_WINDOW)) | DBG_FUNC_NONE, + current_proc()->p_pid, thread_throttle_level, 0, 0, 0); + } + microuptime(&info->throttle_last_IO_timestamp[thread_throttle_level]); + } + + + if (thread_throttle_level >= THROTTLE_LEVEL_THROTTLED) { + /* + * I'd really like to do the IOSleep here, but + * we may be holding all kinds of filesystem related locks + * and the pages for this I/O marked 'busy'... + * we don't want to cause a normal task to block on + * one of these locks while we're throttling a task marked + * for low priority I/O... we'll mark the uthread and + * do the delay just before we return from the system + * call that triggered this I/O or from vnode_pagein + */ + OSAddAtomic(1, &info->throttle_io_count); + + throttle_info_set_initial_window(ut, info, FALSE, isssd); + } + + return thread_throttle_level; +} + +void * +throttle_info_update_by_mount(mount_t mp) +{ + struct _throttle_io_info_t *info; + uthread_t ut; + boolean_t isssd = FALSE; + + ut = get_bsdthread_info(current_thread()); + + if (mp != NULL) { + if (disk_conditioner_mount_is_ssd(mp)) { + isssd = TRUE; + } + info = &_throttle_io_info[mp->mnt_devbsdunit]; + } else { + info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; + } + + if (!ut->uu_lowpri_window) { + throttle_info_set_initial_window(ut, info, FALSE, isssd); + } + + return info; +} + + +/* + * KPI routine + * + * this is usually called before every I/O, used for throttled I/O + * book keeping. This routine has low overhead and does not sleep + */ +void +throttle_info_update(void *throttle_info, int flags) +{ + if (throttle_info) { + throttle_info_update_internal(throttle_info, NULL, flags, FALSE, FALSE, NULL); + } +} + +/* + * KPI routine + * + * this is usually called before every I/O, used for throttled I/O + * book keeping. This routine has low overhead and does not sleep + */ +void +throttle_info_update_by_mask(void *throttle_info_handle, int flags) +{ + void *throttle_info = throttle_info_handle; + + /* + * for now we only use the lowest bit of the throttle mask, so the + * handle is the same as the throttle_info. Later if we store a + * set of throttle infos in the handle, we will want to loop through + * them and call throttle_info_update in a loop + */ + throttle_info_update(throttle_info, flags); +} +/* + * KPI routine + * + * This routine marks the throttle info as disabled. Used for mount points which + * support I/O scheduling. + */ + +void +throttle_info_disable_throttle(int devno, boolean_t isfusion) +{ + struct _throttle_io_info_t *info; + + if (devno < 0 || devno >= LOWPRI_MAX_NUM_DEV) { + panic("Illegal devno (%d) passed into throttle_info_disable_throttle()", devno); + } + + info = &_throttle_io_info[devno]; + // don't disable software throttling on devices that are part of a fusion device + // and override the software throttle periods to use HDD periods + if (isfusion) { + info->throttle_is_fusion_with_priority = isfusion; + throttle_init_throttle_period(info, FALSE); + } + info->throttle_disabled = !info->throttle_is_fusion_with_priority; + return; +} + + +/* + * KPI routine (private) + * Called to determine if this IO is being throttled to this level so that it can be treated specially + */ +int +throttle_info_io_will_be_throttled(void * throttle_info, int policy) { struct _throttle_io_info_t *info = throttle_info; - struct uthread *ut; - int policy; - int is_throttleable_io = 0; - int is_passive_io = 0; - - if (!lowpri_IO_initial_window_msecs || (info == NULL)) - return; - policy = throttle_get_io_policy(&ut); + struct timeval elapsed; + uint64_t elapsed_msecs; + int throttle_level; + int thread_throttle_level; switch (policy) { - case IOPOL_DEFAULT: - case IOPOL_NORMAL: - break; case IOPOL_THROTTLE: - is_throttleable_io = 1; + thread_throttle_level = THROTTLE_LEVEL_TIER3; break; - case IOPOL_PASSIVE: - is_passive_io = 1; + case IOPOL_UTILITY: + thread_throttle_level = THROTTLE_LEVEL_TIER2; + break; + case IOPOL_STANDARD: + thread_throttle_level = THROTTLE_LEVEL_TIER1; break; default: - printf("unknown I/O policy %d", policy); + thread_throttle_level = THROTTLE_LEVEL_TIER0; break; } + for (throttle_level = THROTTLE_LEVEL_START; throttle_level < thread_throttle_level; throttle_level++) { + if (info->throttle_inflight_count[throttle_level]) { + break; + } - if (!is_throttleable_io && ISSET(flags, B_PASSIVE)) - is_passive_io |= 1; + microuptime(&elapsed); + timevalsub(&elapsed, &info->throttle_window_start_timestamp[throttle_level]); + elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000); - if (!is_throttleable_io) { - if (!is_passive_io){ - microuptime(&info->last_normal_IO_timestamp); + if (elapsed_msecs < (uint64_t)throttle_windows_msecs[thread_throttle_level]) { + break; } - } else if (ut) { + } + if (throttle_level >= thread_throttle_level) { /* - * I'd really like to do the IOSleep here, but - * we may be holding all kinds of filesystem related locks - * and the pages for this I/O marked 'busy'... - * we don't want to cause a normal task to block on - * one of these locks while we're throttling a task marked - * for low priority I/O... we'll mark the uthread and - * do the delay just before we return from the system - * call that triggered this I/O or from vnode_pagein + * we're beyond all of the throttle windows + * so go ahead and treat as normal I/O */ - if (ut->uu_lowpri_window == 0) - throttle_info_set_initial_window(ut, info, isssd, FALSE); - else { - /* The thread sends I/Os to different devices within the same system call */ - if (ut->uu_throttle_info != info) { - struct _throttle_io_info_t *old_info = ut->uu_throttle_info; - - // keep track of the numthreads in the right device - OSDecrementAtomic(&old_info->numthreads_throttling); - OSIncrementAtomic(&info->numthreads_throttling); - - DEBUG_ALLOC_THROTTLE_INFO("switching from info = %p\n", old_info, old_info ); - DEBUG_ALLOC_THROTTLE_INFO("switching to info = %p\n", info, info ); - /* This thread no longer needs a reference on that throttle info */ - throttle_info_rel(ut->uu_throttle_info); - ut->uu_throttle_info = info; - /* Need to take a reference on this throttle info */ - throttle_info_ref(ut->uu_throttle_info); - } - int numthreads = MAX(1, info->numthreads_throttling); - ut->uu_lowpri_window += lowpri_IO_window_msecs_inc * numthreads; - if (ut->uu_lowpri_window > lowpri_max_window_msecs * numthreads) - ut->uu_lowpri_window = lowpri_max_window_msecs * numthreads; - - if (isssd == FALSE) { - /* - * we're here because we've actually issued I/Os to different devices... - * if at least one of them was a non SSD, then thottle the thread - * using the policy for non SSDs - */ - ut->uu_throttle_isssd = FALSE; - } - } + return THROTTLE_DISENGAGED; } + /* + * we're in the throttle window + */ + return THROTTLE_ENGAGED; } -/* - * KPI routine - * - * this is usually called before every I/O, used for throttled I/O - * book keeping. This routine has low overhead and does not sleep - */ -void throttle_info_update(void *throttle_info, int flags) +int +throttle_lowpri_window(void) { - throttle_info_update_internal(throttle_info, flags, FALSE); + struct uthread *ut = get_bsdthread_info(current_thread()); + return ut->uu_lowpri_window; } -/* - * KPI routine - * - * this is usually called before every I/O, used for throttled I/O - * book keeping. This routine has low overhead and does not sleep - */ -void throttle_info_update_by_mask(void *throttle_info_handle, int flags) -{ - void *throttle_info = throttle_info_handle; - /* for now we only use the lowest bit of the throttle mask, so the - * handle is the same as the throttle_info. Later if we store a - * set of throttle infos in the handle, we will want to loop through - * them and call throttle_info_update in a loop - */ - throttle_info_update(throttle_info, flags); -} -extern int ignore_is_ssd; +#if CONFIG_IOSCHED +int upl_get_cached_tier(void *); +#endif int spec_strategy(struct vnop_strategy_args *ap) { - buf_t bp; - int bflags; - int policy; - dev_t bdev; + buf_t bp; + int bflags; + int io_tier; + int passive; + dev_t bdev; uthread_t ut; mount_t mp; - int strategy_ret; + struct bufattr *bap; + int strategy_ret; struct _throttle_io_info_t *throttle_info; boolean_t isssd = FALSE; + boolean_t inflight = FALSE; + boolean_t upgrade = FALSE; + int code = 0; + +#if !CONFIG_EMBEDDED + proc_t curproc = current_proc(); +#endif /* !CONFIG_EMBEDDED */ - bp = ap->a_bp; + bp = ap->a_bp; bdev = buf_device(bp); mp = buf_vnode(bp)->v_mount; + bap = &bp->b_attr; + +#if CONFIG_IOSCHED + if (bp->b_flags & B_CLUSTER) { + io_tier = upl_get_cached_tier(bp->b_upl); + + if (io_tier == -1) { + io_tier = throttle_get_io_policy(&ut); + } +#if DEVELOPMENT || DEBUG + else { + int my_io_tier = throttle_get_io_policy(&ut); + + if (io_tier != my_io_tier) { + KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_THROTTLE, IO_TIER_UPL_MISMATCH)) | DBG_FUNC_NONE, buf_kernel_addrperm_addr(bp), my_io_tier, io_tier, 0, 0); + } + } +#endif + } else { + io_tier = throttle_get_io_policy(&ut); + } +#else + io_tier = throttle_get_io_policy(&ut); +#endif + passive = throttle_get_passive_io_policy(&ut); + + /* + * Mark if the I/O was upgraded by throttle_get_thread_throttle_level + * while preserving the original issued tier (throttle_get_io_policy + * does not return upgraded tiers) + */ + if (mp && io_tier > throttle_get_thread_throttle_level_internal(ut, io_tier)) { +#if CONFIG_IOSCHED + if (!(mp->mnt_ioflags & MNT_IOFLAGS_IOSCHED_SUPPORTED)) { + upgrade = TRUE; + } +#else /* CONFIG_IOSCHED */ + upgrade = TRUE; +#endif /* CONFIG_IOSCHED */ + } + + if (bp->b_flags & B_META) { + bap->ba_flags |= BA_META; + } + +#if CONFIG_IOSCHED + /* + * For I/O Scheduling, we currently do not have a way to track and expedite metadata I/Os. + * To ensure we dont get into priority inversions due to metadata I/Os, we use the following rules: + * For metadata reads, ceil all I/Os to IOSCHED_METADATA_TIER & mark them passive if the I/O tier was upgraded + * For metadata writes, unconditionally mark them as IOSCHED_METADATA_TIER and passive + */ + if (bap->ba_flags & BA_META) { + if ((mp && (mp->mnt_ioflags & MNT_IOFLAGS_IOSCHED_SUPPORTED)) || (bap->ba_flags & BA_IO_SCHEDULED)) { + if (bp->b_flags & B_READ) { + if (io_tier > IOSCHED_METADATA_TIER) { + io_tier = IOSCHED_METADATA_TIER; + passive = 1; + } + } else { + io_tier = IOSCHED_METADATA_TIER; + passive = 1; + } + } + } +#endif /* CONFIG_IOSCHED */ - policy = throttle_get_io_policy(&ut); + SET_BUFATTR_IO_TIER(bap, io_tier); - if (policy == IOPOL_THROTTLE) { - bp->b_flags |= B_THROTTLED_IO; - bp->b_attr.ba_flags |= BA_THROTTLED_IO; - bp->b_flags &= ~B_PASSIVE; - } else if (policy == IOPOL_PASSIVE) + if (passive) { bp->b_flags |= B_PASSIVE; + bap->ba_flags |= BA_PASSIVE; + } + +#if !CONFIG_EMBEDDED + if ((curproc != NULL) && ((curproc->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP)) { + bap->ba_flags |= BA_DELAYIDLESLEEP; + } +#endif /* !CONFIG_EMBEDDED */ bflags = bp->b_flags; - if (kdebug_enable) { - int code = 0; + if (((bflags & B_READ) == 0) && ((bflags & B_ASYNC) == 0)) { + bufattr_markquickcomplete(bap); + } + + if (bflags & B_READ) { + code |= DKIO_READ; + } + if (bflags & B_ASYNC) { + code |= DKIO_ASYNC; + } + + if (bap->ba_flags & BA_META) { + code |= DKIO_META; + } else if (bflags & B_PAGEIO) { + code |= DKIO_PAGING; + } + + if (io_tier != 0) { + code |= DKIO_THROTTLE; + } + + code |= ((io_tier << DKIO_TIER_SHIFT) & DKIO_TIER_MASK); + + if (bflags & B_PASSIVE) { + code |= DKIO_PASSIVE; + } - if (bflags & B_READ) - code |= DKIO_READ; - if (bflags & B_ASYNC) - code |= DKIO_ASYNC; + if (bap->ba_flags & BA_NOCACHE) { + code |= DKIO_NOCACHE; + } - if (bflags & B_META) - code |= DKIO_META; - else if (bflags & B_PAGEIO) - code |= DKIO_PAGING; + if (upgrade) { + code |= DKIO_TIER_UPGRADE; + SET(bap->ba_flags, BA_IO_TIER_UPGRADE); + } - if (bflags & B_THROTTLED_IO) - code |= DKIO_THROTTLE; - else if (bflags & B_PASSIVE) - code |= DKIO_PASSIVE; + if (kdebug_enable) { + KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON, FSDBG_CODE(DBG_DKRW, code) | DBG_FUNC_NONE, + buf_kernel_addrperm_addr(bp), bdev, buf_blkno(bp), buf_count(bp), 0); + } - KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_DKRW, code) | DBG_FUNC_NONE, - bp, bdev, (int)buf_blkno(bp), buf_count(bp), 0); - } - if (((bflags & (B_IOSTREAMING | B_PAGEIO | B_READ)) == (B_PAGEIO | B_READ)) && - mp && (mp->mnt_kern_flag & MNTK_ROOTDEV)) - hard_throttle_on_root = 1; + thread_update_io_stats(current_thread(), buf_count(bp), code); if (mp != NULL) { - if ((mp->mnt_kern_flag & MNTK_SSD) && !ignore_is_ssd) + if (disk_conditioner_mount_is_ssd(mp)) { isssd = TRUE; + } + /* + * Partially initialized mounts don't have a final devbsdunit and should not be tracked. + * Verify that devbsdunit is initialized (non-zero) or that 0 is the correct initialized value + * (mnt_throttle_mask is initialized and num_trailing_0 would be 0) + */ + if (mp->mnt_devbsdunit || (mp->mnt_throttle_mask != LOWPRI_MAX_NUM_DEV - 1 && mp->mnt_throttle_mask & 0x1)) { + inflight = TRUE; + } throttle_info = &_throttle_io_info[mp->mnt_devbsdunit]; - } else + } else { throttle_info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1]; + } - throttle_info_update_internal(throttle_info, bflags, isssd); + throttle_info_update_internal(throttle_info, ut, bflags, isssd, inflight, bap); if ((bflags & B_READ) == 0) { - microuptime(&throttle_info->last_IO_timestamp); + microuptime(&throttle_info->throttle_last_write_timestamp); + if (mp) { + mp->mnt_last_write_issued_timestamp = throttle_info->throttle_last_write_timestamp; INCR_PENDING_IO(buf_count(bp), mp->mnt_pending_write_size); } } else if (mp) { @@ -1331,32 +2612,36 @@ spec_strategy(struct vnop_strategy_args *ap) * the boot cache too often. * * Note that typical strategy routines are defined with - * a void return so we'll get garbage here. In the + * a void return so we'll get garbage here. In the * unlikely case the garbage matches our special return * value, it's not a big deal since we're only adjusting * the throttling delay. - */ + */ #define IO_SATISFIED_BY_CACHE ((int)0xcafefeed) #define IO_SHOULD_BE_THROTTLED ((int)0xcafebeef) - typedef int strategy_fcn_ret_t(struct buf *bp); - + typedef int strategy_fcn_ret_t(struct buf *bp); + strategy_ret = (*(strategy_fcn_ret_t*)bdevsw[major(bdev)].d_strategy)(bp); - - if ((IO_SATISFIED_BY_CACHE == strategy_ret) && (ut->uu_lowpri_window != 0) && (ut->uu_throttle_info != NULL)) { + + // disk conditioner needs to track when this I/O actually starts + // which means track it after `strategy` which may include delays + // from inflight I/Os + microuptime(&bp->b_timestamp_tv); + + if (IO_SATISFIED_BY_CACHE == strategy_ret) { /* * If this was a throttled IO satisfied by the boot cache, * don't delay the thread. */ throttle_info_reset_window(ut); - - } else if ((IO_SHOULD_BE_THROTTLED == strategy_ret) && (ut->uu_lowpri_window == 0) && (ut->uu_throttle_info == NULL)) { + } else if (IO_SHOULD_BE_THROTTLED == strategy_ret) { /* * If the boot cache indicates this IO should be throttled, * delay the thread. */ - throttle_info_set_initial_window(ut, throttle_info, isssd, TRUE); + throttle_info_set_initial_window(ut, throttle_info, TRUE, isssd); } - return (0); + return 0; } @@ -1366,7 +2651,7 @@ spec_strategy(struct vnop_strategy_args *ap) int spec_blockmap(__unused struct vnop_blockmap_args *ap) { - return (ENOTSUP); + return ENOTSUP; } @@ -1382,10 +2667,8 @@ spec_close(struct vnop_close_args *ap) int flags = ap->a_fflag; struct proc *p = vfs_context_proc(ap->a_context); struct session *sessp; - int do_rele = 0; switch (vp->v_type) { - case VCHR: /* * Hack: a tty device that is a controlling terminal @@ -1394,46 +2677,52 @@ spec_close(struct vnop_close_args *ap) * a controlling terminal, unless it is the closing * process' controlling terminal. In that case, * if the reference count is 1 (this is the very - * last close) + * last close) */ sessp = proc_session(p); + devsw_lock(dev, S_IFCHR); if (sessp != SESSION_NULL) { - if ((vcount(vp) == 1) && - (vp == sessp->s_ttyvp)) { + if (vp == sessp->s_ttyvp && vcount(vp) == 1) { + struct tty *tp = TTY_NULL; + devsw_unlock(dev, S_IFCHR); session_lock(sessp); if (vp == sessp->s_ttyvp) { + tp = SESSION_TP(sessp); sessp->s_ttyvp = NULL; sessp->s_ttyvid = 0; sessp->s_ttyp = TTY_NULL; sessp->s_ttypgrpid = NO_PID; - do_rele = 1; - } + } session_unlock(sessp); - if (do_rele) { - vnode_rele(vp); + if (tp != TTY_NULL) { + /* + * We may have won a race with a proc_exit + * of the session leader, the winner + * clears the flag (even if not set) + */ + tty_lock(tp); + ttyclrpgrphup(tp); + tty_unlock(tp); + + ttyfree(tp); } + devsw_lock(dev, S_IFCHR); } session_rele(sessp); } - devsw_lock(dev, S_IFCHR); - - vp->v_specinfo->si_opencount--; - - if (vp->v_specinfo->si_opencount < 0) { - panic("Negative open count?"); + if (--vp->v_specinfo->si_opencount < 0) { + panic("negative open count (c, %u, %u)", major(dev), minor(dev)); } + /* * close on last reference or on vnode revoke call */ - if ((vcount(vp) > 0) && ((flags & IO_REVOKE) == 0)) { - devsw_unlock(dev, S_IFCHR); - return (0); - } - - error = cdevsw[major(dev)].d_close(dev, flags, S_IFCHR, p); + if (vcount(vp) == 0 || (flags & IO_REVOKE) != 0) { + error = cdevsw[major(dev)].d_close(dev, flags, S_IFCHR, p); + } devsw_unlock(dev, S_IFCHR); break; @@ -1447,7 +2736,7 @@ spec_close(struct vnop_close_args *ap) if (vcount(vp) > 1) { vp->v_specinfo->si_opencount--; devsw_unlock(dev, S_IFBLK); - return (0); + return 0; } devsw_unlock(dev, S_IFBLK); @@ -1456,34 +2745,31 @@ spec_close(struct vnop_close_args *ap) * we must invalidate any in core blocks, so that * we can, for instance, change floppy disks. */ - if ((error = spec_fsync_internal(vp, MNT_WAIT, ap->a_context))) - return (error); + if ((error = spec_fsync_internal(vp, MNT_WAIT, ap->a_context))) { + return error; + } error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0); - if (error) - return (error); + if (error) { + return error; + } devsw_lock(dev, S_IFBLK); - vp->v_specinfo->si_opencount--; - - if (vp->v_specinfo->si_opencount < 0) { - panic("Negative open count?"); + if (--vp->v_specinfo->si_opencount < 0) { + panic("negative open count (b, %u, %u)", major(dev), minor(dev)); } - if (vcount(vp) > 0) { - devsw_unlock(dev, S_IFBLK); - return (0); + if (vcount(vp) == 0) { + error = bdevsw[major(dev)].d_close(dev, flags, S_IFBLK, p); } - error = bdevsw[major(dev)].d_close(dev, flags, S_IFBLK, p); - devsw_unlock(dev, S_IFBLK); break; default: panic("spec_close: not special"); - return(EBADF); + return EBADF; } return error; @@ -1495,28 +2781,27 @@ spec_close(struct vnop_close_args *ap) int spec_pathconf(struct vnop_pathconf_args *ap) { - switch (ap->a_name) { case _PC_LINK_MAX: *ap->a_retval = LINK_MAX; - return (0); + return 0; case _PC_MAX_CANON: *ap->a_retval = MAX_CANON; - return (0); + return 0; case _PC_MAX_INPUT: *ap->a_retval = MAX_INPUT; - return (0); + return 0; case _PC_PIPE_BUF: *ap->a_retval = PIPE_BUF; - return (0); + return 0; case _PC_CHOWN_RESTRICTED: - *ap->a_retval = 200112; /* _POSIX_CHOWN_RESTRICTED */ - return (0); + *ap->a_retval = 200112; /* _POSIX_CHOWN_RESTRICTED */ + return 0; case _PC_VDISABLE: *ap->a_retval = _POSIX_VDISABLE; - return (0); + return 0; default: - return (EINVAL); + return EINVAL; } /* NOTREACHED */ } @@ -1527,8 +2812,7 @@ spec_pathconf(struct vnop_pathconf_args *ap) int spec_ebadf(__unused void *dummy) { - - return (EBADF); + return EBADF; } /* Blktooff derives file offset from logical block number */ @@ -1540,19 +2824,19 @@ spec_blktooff(struct vnop_blktooff_args *ap) switch (vp->v_type) { case VCHR: *ap->a_offset = (off_t)-1; /* failure */ - return (ENOTSUP); + return ENOTSUP; case VBLK: printf("spec_blktooff: not implemented for VBLK\n"); *ap->a_offset = (off_t)-1; /* failure */ - return (ENOTSUP); + return ENOTSUP; default: panic("spec_blktooff type"); } /* NOTREACHED */ - return (0); + return 0; } /* Offtoblk derives logical block number from file offset */ @@ -1564,50 +2848,194 @@ spec_offtoblk(struct vnop_offtoblk_args *ap) switch (vp->v_type) { case VCHR: *ap->a_lblkno = (daddr64_t)-1; /* failure */ - return (ENOTSUP); + return ENOTSUP; case VBLK: printf("spec_offtoblk: not implemented for VBLK\n"); *ap->a_lblkno = (daddr64_t)-1; /* failure */ - return (ENOTSUP); + return ENOTSUP; default: panic("spec_offtoblk type"); } /* NOTREACHED */ - return (0); + return 0; } static void filt_specdetach(struct knote *kn); -static int filt_spec(struct knote *kn, long hint); -static unsigned filt_specpeek(struct knote *kn); - -struct filterops spec_filtops = { - .f_isfd = 1, - .f_attach = filt_specattach, - .f_detach = filt_specdetach, - .f_event = filt_spec, - .f_peek = filt_specpeek +static int filt_specevent(struct knote *kn, long hint); +static int filt_spectouch(struct knote *kn, struct kevent_qos_s *kev); +static int filt_specprocess(struct knote *kn, struct kevent_qos_s *kev); +static int filt_specpeek(struct knote *kn); + +SECURITY_READ_ONLY_EARLY(struct filterops) spec_filtops = { + .f_isfd = 1, + .f_attach = filt_specattach, + .f_detach = filt_specdetach, + .f_event = filt_specevent, + .f_touch = filt_spectouch, + .f_process = filt_specprocess, + .f_peek = filt_specpeek }; + +/* + * Given a waitq that is assumed to be embedded within a selinfo structure, + * return the containing selinfo structure. While 'wq' is not really a queue + * element, this macro simply does the offset_of calculation to get back to a + * containing struct given the struct type and member name. + */ +#define selinfo_from_waitq(wq) \ + qe_element((wq), struct selinfo, si_waitq) + static int -filter_to_seltype(int16_t filter) +spec_knote_select_and_link(struct knote *kn) { - switch (filter) { - case EVFILT_READ: - return FREAD; - case EVFILT_WRITE: - return FWRITE; - break; - default: - panic("filt_to_seltype(): invalid filter %d\n", filter); + uthread_t uth; + vfs_context_t ctx; + vnode_t vp; + struct waitq_set *old_wqs; + uint64_t rsvd, rsvd_arg; + uint64_t *rlptr = NULL; + struct selinfo *si = NULL; + int selres = 0; + + uth = get_bsdthread_info(current_thread()); + + ctx = vfs_context_current(); + vp = (vnode_t)kn->kn_fp->f_fglob->fg_data; + + int error = vnode_getwithvid(vp, vnode_vid(vp)); + if (error != 0) { + knote_set_error(kn, ENOENT); return 0; } + + /* + * This function may be called many times to link or re-link the + * underlying vnode to the kqueue. If we've already linked the two, + * we will have a valid kn_hook_waitqid which ties us to the underlying + * device's waitq via a the waitq's prepost table object. However, + * devices can abort any select action by calling selthreadclear(). + * This is OK because the table object will be invalidated by the + * driver (through a call to selthreadclear), so any attempt to access + * the associated waitq will fail because the table object is invalid. + * + * Even if we've already registered, we need to pass a pointer + * to a reserved link structure. Otherwise, selrecord() will + * infer that we're in the second pass of select() and won't + * actually do anything! + */ + rsvd = rsvd_arg = waitq_link_reserve(NULL); + rlptr = (void *)&rsvd_arg; + + /* + * Trick selrecord() into hooking kqueue's wait queue set into the device's + * selinfo wait queue. + */ + old_wqs = uth->uu_wqset; + uth->uu_wqset = &(knote_get_kq(kn)->kq_wqs); + + /* + * Be sure that the waitq set is linked + * before calling select to avoid possible + * allocation under spinlocks. + */ + waitq_set_lazy_init_link(uth->uu_wqset); + + /* + * Now these are the laws of VNOP_SELECT, as old and as true as the sky, + * And the device that shall keep it may prosper, but the device that shall + * break it must receive ENODEV: + * + * 1. Take a lock to protect against other selects on the same vnode. + * 2. Return 1 if data is ready to be read. + * 3. Return 0 and call `selrecord` on a handy `selinfo` structure if there + * is no data. + * 4. Call `selwakeup` when the vnode has an active `selrecord` and data + * can be read or written (depending on the seltype). + * 5. If there's a `selrecord` and no corresponding `selwakeup`, but the + * vnode is going away, call `selthreadclear`. + */ + selres = VNOP_SELECT(vp, knote_get_seltype(kn), 0, rlptr, ctx); + uth->uu_wqset = old_wqs; + + /* + * Make sure to cleanup the reserved link - this guards against + * drivers that may not actually call selrecord(). + */ + waitq_link_release(rsvd); + if (rsvd != rsvd_arg) { + /* The driver / handler called selrecord() */ + struct waitq *wq; + memcpy(&wq, rlptr, sizeof(void *)); + + /* + * The waitq is part of the selinfo structure managed by the + * driver. For certain drivers, we want to hook the knote into + * the selinfo structure's si_note field so selwakeup can call + * KNOTE. + */ + si = selinfo_from_waitq(wq); + + /* + * The waitq_get_prepost_id() function will (potentially) + * allocate a prepost table object for the waitq and return + * the table object's ID to us. It will also set the + * waitq_prepost_id field within the waitq structure. + * + * We can just overwrite kn_hook_waitqid because it's simply a + * table ID used to grab a reference when needed. + * + * We have a reference on the vnode, so we know that the + * device won't go away while we get this ID. + * + * Note: on 32bit this field is 32bit only. + */ + kn->kn_hook_waitqid = (typeof(kn->kn_hook_waitqid))waitq_get_prepost_id(wq); + } else if (selres == 0) { + /* + * The device indicated that there's no data to read, but didn't call + * `selrecord`. Nothing will be notified of changes to this vnode, so + * return an error back to user space, to make it clear that the knote + * is not attached. + */ + knote_set_error(kn, ENODEV); + } + + vnode_put(vp); + + return selres; +} + +static int +filt_spec_common(struct knote *kn, struct kevent_qos_s *kev, int selres) +{ + int64_t data; + int ret; + + if (kn->kn_vnode_use_ofst) { + if (kn->kn_fp->f_fglob->fg_offset >= (uint32_t)selres) { + data = 0; + } else { + data = ((uint32_t)selres) - kn->kn_fp->f_fglob->fg_offset; + } + } else { + data = selres; + } + + ret = data >= knote_low_watermark(kn); + + if (ret && kev) { + knote_fill_kevent(kn, kev, data); + } + + return ret; } -static int -filt_specattach(struct knote *kn) +static int +filt_specattach(struct knote *kn, __unused struct kevent_qos_s *kev) { vnode_t vp; dev_t dev; @@ -1618,131 +3046,117 @@ filt_specattach(struct knote *kn) dev = vnode_specrdev(vp); - if (major(dev) > nchrdev) { - return ENXIO; + /* + * For a few special kinds of devices, we can attach knotes with + * no restrictions because their "select" vectors return the amount + * of data available. Others require an explicit NOTE_LOWAT with + * data of 1, indicating that the caller doesn't care about actual + * data counts, just an indication that the device has data. + */ + if (!kn->kn_vnode_kqok && + ((kn->kn_sfflags & NOTE_LOWAT) == 0 || kn->kn_sdata != 1)) { + knote_set_error(kn, EINVAL); + return 0; } - if ((cdevsw_flags[major(dev)] & CDEVSW_SELECT_KQUEUE) == 0) { - return EINVAL; + /* + * This forces the select fallback to call through VNOP_SELECT and hook + * up selinfo on every filter routine. + * + * Pseudo-terminal controllers are opted out of native kevent support -- + * remove this when they get their own EVFILTID. + */ + if (cdevsw_flags[major(dev)] & CDEVSW_IS_PTC) { + kn->kn_vnode_kqok = 0; } - /* Resulting wql is safe to unlink even if it has never been linked */ - kn->kn_hook = wait_queue_link_allocate(); - if (kn->kn_hook == NULL) { - return EAGAIN; - } + kn->kn_filtid = EVFILTID_SPEC; + kn->kn_hook_waitqid = 0; + + knote_markstayactive(kn); + return spec_knote_select_and_link(kn); +} - kn->kn_fop = &spec_filtops; - kn->kn_hookid = vnode_vid(vp); +static void +filt_specdetach(struct knote *kn) +{ + knote_clearstayactive(kn); - knote_markstayqueued(kn); + /* + * This is potentially tricky: the device's selinfo waitq that was + * tricked into being part of this knote's waitq set may not be a part + * of any other set, and the device itself may have revoked the memory + * in which the waitq was held. We use the knote's kn_hook_waitqid field + * to keep the ID of the waitq's prepost table object. This + * object keeps a pointer back to the waitq, and gives us a safe way + * to decouple the dereferencing of driver allocated memory: if the + * driver goes away (taking the waitq with it) then the prepost table + * object will be invalidated. The waitq details are handled in the + * waitq API invoked here. + */ + if (kn->kn_hook_waitqid) { + waitq_unlink_by_prepost_id(kn->kn_hook_waitqid, &(knote_get_kq(kn)->kq_wqs)); + kn->kn_hook_waitqid = 0; + } +} +static int +filt_specevent(struct knote *kn, __unused long hint) +{ + /* + * Nothing should call knote or knote_vanish on this knote. + */ + panic("filt_specevent(%p)", kn); return 0; } -static void -filt_specdetach(struct knote *kn) +static int +filt_spectouch(struct knote *kn, struct kevent_qos_s *kev) { - kern_return_t ret; + kn->kn_sdata = kev->data; + kn->kn_sfflags = kev->fflags; - /* - * Given wait queue link and wait queue set, unlink. This is subtle. - * If the device has been revoked from under us, selclearthread() will - * have removed our link from the kqueue's wait queue set, which - * wait_queue_set_unlink_one() will detect and handle. - */ - ret = wait_queue_set_unlink_one(kn->kn_kq->kq_wqs, kn->kn_hook); - if (ret != KERN_SUCCESS) { - panic("filt_specdetach(): failed to unlink wait queue link."); + if (kev->flags & EV_ENABLE) { + return spec_knote_select_and_link(kn); } - (void)wait_queue_link_free(kn->kn_hook); - kn->kn_hook = NULL; - kn->kn_status &= ~KN_STAYQUEUED; + return 0; } -static int -filt_spec(struct knote *kn, long hint) +static int +filt_specprocess(struct knote *kn, struct kevent_qos_s *kev) { vnode_t vp; uthread_t uth; - wait_queue_set_t old_wqs; vfs_context_t ctx; + int res; int selres; int error; - int use_offset; - dev_t dev; - uint64_t flags; - - assert(kn->kn_hook != NULL); - - if (hint != 0) { - panic("filt_spec(): nonzero hint?"); - } uth = get_bsdthread_info(current_thread()); ctx = vfs_context_current(); vp = (vnode_t)kn->kn_fp->f_fglob->fg_data; - error = vnode_getwithvid(vp, kn->kn_hookid); + error = vnode_getwithvid(vp, vnode_vid(vp)); if (error != 0) { kn->kn_flags |= (EV_EOF | EV_ONESHOT); + knote_fill_kevent(kn, kev, 0); return 1; } - - dev = vnode_specrdev(vp); - flags = cdevsw_flags[major(dev)]; - use_offset = ((flags & CDEVSW_USE_OFFSET) != 0); - assert((flags & CDEVSW_SELECT_KQUEUE) != 0); - - /* Trick selrecord() into hooking kqueue's wait queue set into device wait queue */ - old_wqs = uth->uu_wqset; - uth->uu_wqset = kn->kn_kq->kq_wqs; - selres = VNOP_SELECT(vp, filter_to_seltype(kn->kn_filter), 0, kn->kn_hook, ctx); - uth->uu_wqset = old_wqs; - if (use_offset) { - if (kn->kn_fp->f_fglob->fg_offset >= (uint32_t)selres) { - kn->kn_data = 0; - } else { - kn->kn_data = ((uint32_t)selres) - kn->kn_fp->f_fglob->fg_offset; - } - } else { - kn->kn_data = selres; - } + selres = spec_knote_select_and_link(kn); + res = filt_spec_common(kn, kev, selres); vnode_put(vp); - return (kn->kn_data != 0); + return res; } -static unsigned +static int filt_specpeek(struct knote *kn) { - vnode_t vp; - uthread_t uth; - wait_queue_set_t old_wqs; - vfs_context_t ctx; - int error, selres; - - uth = get_bsdthread_info(current_thread()); - ctx = vfs_context_current(); - vp = (vnode_t)kn->kn_fp->f_fglob->fg_data; - - error = vnode_getwithvid(vp, kn->kn_hookid); - if (error != 0) { - return 1; /* Just like VNOP_SELECT() on recycled vnode */ - } + int selres = 0; - /* - * Why pass the link here? Because we may not have registered in the past... - */ - old_wqs = uth->uu_wqset; - uth->uu_wqset = kn->kn_kq->kq_wqs; - selres = VNOP_SELECT(vp, filter_to_seltype(kn->kn_filter), 0, kn->kn_hook, ctx); - uth->uu_wqset = old_wqs; - - vnode_put(vp); - return selres; + selres = spec_knote_select_and_link(kn); + return filt_spec_common(kn, NULL, selres); } -