xnu-1228.15.4.tar.gz

[apple/xnu.git] / bsd / miscfs / specfs / spec_vnops.c

diff --git a/bsd/miscfs/specfs/spec_vnops.c b/bsd/miscfs/specfs/spec_vnops.c
index aad1b0250e1d9f5cad5ca0c166c6c54ef09c82db..6c26b1799734bcec0b423c8747d8e095861e1962 100644 (file)
--- a/bsd/miscfs/specfs/spec_vnops.c
+++ b/bsd/miscfs/specfs/spec_vnops.c
@@ -600,6 +600,7 @@ void IOSleep(int);
 
 struct _throttle_io_info_t {
        struct timeval  last_normal_IO_timestamp;
+       struct timeval  last_IO_timestamp;
        SInt32 numthreads_throttling;
 };
 
@@ -614,6 +615,32 @@ SYSCTL_INT(_debug, OID_AUTO, lowpri_IO_window_inc, CTLFLAG_RW, &lowpri_IO_window
 SYSCTL_INT(_debug, OID_AUTO, lowpri_max_window_msecs, CTLFLAG_RW, &lowpri_max_window_msecs, LOWPRI_INITIAL_WINDOW_MSECS, "");
 SYSCTL_INT(_debug, OID_AUTO, lowpri_max_waiting_msecs, CTLFLAG_RW, &lowpri_max_waiting_msecs, LOWPRI_INITIAL_WINDOW_MSECS, "");
 
+void
+throttle_info_get_last_io_time(mount_t mp, struct timeval *tv)
+{
+       size_t devbsdunit;
+               
+       devbsdunit = mp->mnt_devbsdunit;
+
+       if (devbsdunit < LOWPRI_MAX_NUM_DEV) {
+               *tv = _throttle_io_info[devbsdunit].last_IO_timestamp;
+       } else {
+               memset(tv, 0, sizeof(*tv));
+       }
+}
+
+void
+update_last_io_time(mount_t mp)
+{
+       size_t devbsdunit;
+               
+       devbsdunit = mp->mnt_devbsdunit;
+
+       if (devbsdunit < LOWPRI_MAX_NUM_DEV) {
+               microuptime(&_throttle_io_info[devbsdunit].last_IO_timestamp);
+       }
+}
+
 int throttle_io_will_be_throttled(int lowpri_window_msecs, size_t devbsdunit)
 {
        struct timeval elapsed;
@@ -784,6 +811,18 @@ spec_strategy(struct vnop_strategy_args *ap)
                        }
                }
        }
+
+       if ((bflags & B_READ) == 0) {
+               size_t devbsdunit;
+
+               if (buf_vnode(bp)->v_mount != NULL)
+                       devbsdunit = buf_vnode(bp)->v_mount->mnt_devbsdunit;
+               else
+                       devbsdunit = LOWPRI_MAX_NUM_DEV - 1;
+               
+               microuptime(&_throttle_io_info[devbsdunit].last_IO_timestamp);
+       }
+
         (*bdevsw[major(bdev)].d_strategy)(bp);
 
         return (0);