osfmk/kern/kpc_thread.c

   1 /*
   2  * Copyright (c) 2012 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <mach/mach_types.h>
  30 #include <kern/processor.h>
  31 #include <kern/thread.h>
  32 #include <kern/assert.h>
  33 #include <kern/locks.h>
  34 #include <sys/errno.h>
  35
  36 #include <kperf/kperf.h>
  37 #include <kperf/buffer.h>
  38 #include <kperf/context.h>
  39 #include <kperf/sample.h>
  40 #include <kperf/action.h>
  41 #include <kperf/kperf_kpc.h>
  42 #include <kern/kpc.h>
  43
  44
  45 /* global for whether to read PMCs on context switch */
  46 int kpc_threads_counting = 0;
  47
  48 /* current config and number of counters in that config */
  49 static uint32_t kpc_thread_classes = 0;
  50 static uint32_t kpc_thread_classes_count = 0;
  51
  52 static lck_grp_attr_t *kpc_thread_lckgrp_attr = NULL;
  53 static lck_grp_t      *kpc_thread_lckgrp = NULL;
  54 static lck_mtx_t       kpc_thread_lock;
  55
  56 void
  57 kpc_thread_init(void)
  58 {
  59         kpc_thread_lckgrp_attr = lck_grp_attr_alloc_init();
  60         kpc_thread_lckgrp = lck_grp_alloc_init("kpc", kpc_thread_lckgrp_attr);
  61         lck_mtx_init(&kpc_thread_lock, kpc_thread_lckgrp, LCK_ATTR_NULL);
  62 }
  63
  64 uint32_t
  65 kpc_get_thread_counting(void)
  66 {
  67         uint32_t kpc_thread_classes_tmp;
  68         int kpc_threads_counting_tmp;
  69
  70         /* Make sure we get a consistent snapshot of these values */
  71         lck_mtx_lock(&kpc_thread_lock);
  72
  73         kpc_thread_classes_tmp = kpc_thread_classes;
  74         kpc_threads_counting_tmp = kpc_threads_counting;
  75
  76         lck_mtx_unlock(&kpc_thread_lock);
  77
  78         if( kpc_threads_counting_tmp )
  79                 return kpc_thread_classes_tmp;
  80         else
  81                 return 0;
  82 }
  83
  84 int
  85 kpc_set_thread_counting(uint32_t classes)
  86 {
  87         uint32_t count;
  88
  89         lck_mtx_lock(&kpc_thread_lock);
  90
  91         count = kpc_get_counter_count(classes);
  92
  93         if( (classes == 0)
  94             || (count == 0) )
  95         {
  96                 /* shut down */
  97                 kpc_threads_counting = FALSE;
  98         }
  99         else
 100         {
 101                 /* stash the config */
 102                 kpc_thread_classes = classes;
 103
 104                 /* work out the size */
 105                 kpc_thread_classes_count = count;
 106                 assert(kpc_thread_classes_count <= KPC_MAX_COUNTERS);
 107
 108                 /* enable switch */
 109                 kpc_threads_counting = TRUE;
 110
 111                 /* and schedule an AST for this thread... */
 112                 if( !current_thread()->kpc_buf )
 113                 {
 114                         current_thread()->t_chud |= T_KPC_ALLOC;
 115                         act_set_kperf(current_thread());
 116                 }
 117         }
 118
 119     kperf_kpc_cswitch_callback_update();
 120         lck_mtx_unlock(&kpc_thread_lock);
 121
 122         return 0;
 123 }
 124
 125 /* snapshot current PMCs and update counters in the current thread */
 126 static void
 127 kpc_update_thread_counters( thread_t thread )
 128 {
 129         uint32_t i;
 130         uint64_t *tmp = NULL;
 131         cpu_data_t *cpu = NULL;
 132
 133         cpu = current_cpu_datap();
 134
 135         /* 1. stash current PMCs into latest CPU block */
 136         kpc_get_cpu_counters( FALSE, kpc_thread_classes,
 137                               NULL, cpu->cpu_kpc_buf[1] );
 138
 139         /* 2. apply delta to old thread */
 140         if( thread->kpc_buf )
 141                 for( i = 0; i < kpc_thread_classes_count; i++ )
 142                         thread->kpc_buf[i] += cpu->cpu_kpc_buf[1][i] - cpu->cpu_kpc_buf[0][i];
 143
 144
 145         /* schedule any necessary allocations */
 146         if( !current_thread()->kpc_buf )
 147         {
 148                 current_thread()->t_chud |= T_KPC_ALLOC;
 149                 act_set_kperf(current_thread());
 150         }
 151
 152         /* 3. switch the PMC block pointers */
 153         tmp = cpu->cpu_kpc_buf[1];
 154         cpu->cpu_kpc_buf[1] = cpu->cpu_kpc_buf[0];
 155         cpu->cpu_kpc_buf[0] = tmp;
 156 }
 157
 158 void
 159 kpc_switch_context( thread_t old, thread_t new __unused )
 160 {
 161         kpc_update_thread_counters( old );
 162 }
 163
 164 /* get counter values for a thread */
 165 int
 166 kpc_get_curthread_counters(uint32_t *inoutcount, uint64_t *buf)
 167 {
 168         thread_t thread = current_thread();
 169         boolean_t enabled;
 170
 171         /* buffer too small :( */
 172         if( *inoutcount < kpc_thread_classes_count )
 173                 return EINVAL;
 174
 175         /* copy data and actual size */
 176         if( !thread->kpc_buf )
 177                 return EINVAL;
 178
 179         enabled = ml_set_interrupts_enabled(FALSE);
 180
 181         /* snap latest version of counters for this thread */
 182         kpc_update_thread_counters( current_thread() );
 183
 184         /* copy out */
 185         memcpy( buf, thread->kpc_buf,
 186                 kpc_thread_classes_count * sizeof(*buf) );
 187         *inoutcount = kpc_thread_classes_count;
 188
 189         ml_set_interrupts_enabled(enabled);
 190
 191         return 0;
 192 }
 193
 194
 195 void
 196 kpc_thread_create(thread_t thread)
 197 {
 198         /* nothing to do if we're not counting */
 199         if(!kpc_threads_counting)
 200                 return;
 201
 202         /* give the new thread a counterbuf */
 203         thread->kpc_buf = kpc_counterbuf_alloc();
 204 }
 205
 206 void
 207 kpc_thread_destroy(thread_t thread)
 208 {
 209         uint64_t *buf = NULL;
 210
 211         /* usual case: no kpc buf, just return */
 212         if( !thread->kpc_buf )
 213                 return;
 214
 215         /* otherwise, don't leak */
 216         buf = thread->kpc_buf;
 217         thread->kpc_buf = NULL;
 218         kpc_counterbuf_free(buf);
 219 }
 220
 221 /* ast callback on a thread */
 222 void
 223 kpc_thread_ast_handler( thread_t thread )
 224 {
 225         /* see if we want an alloc */
 226         if( thread->t_chud & T_KPC_ALLOC )
 227                 thread->kpc_buf = kpc_counterbuf_alloc();
 228 }