Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 1 | /* delayacct.c - per-task delay accounting |
| 2 | * |
| 3 | * Copyright (C) Shailabh Nagar, IBM Corp. 2006 |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it would be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| 13 | * the GNU General Public License for more details. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/sched.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/time.h> |
| 19 | #include <linux/sysctl.h> |
| 20 | #include <linux/delayacct.h> |
| 21 | |
Shailabh Nagar | 163ecdf | 2006-07-30 03:03:11 -0700 | [diff] [blame] | 22 | int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 23 | struct kmem_cache *delayacct_cache; |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 24 | |
Shailabh Nagar | 163ecdf | 2006-07-30 03:03:11 -0700 | [diff] [blame] | 25 | static int __init delayacct_setup_disable(char *str) |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 26 | { |
Shailabh Nagar | 163ecdf | 2006-07-30 03:03:11 -0700 | [diff] [blame] | 27 | delayacct_on = 0; |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 28 | return 1; |
| 29 | } |
Shailabh Nagar | 163ecdf | 2006-07-30 03:03:11 -0700 | [diff] [blame] | 30 | __setup("nodelayacct", delayacct_setup_disable); |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 31 | |
| 32 | void delayacct_init(void) |
| 33 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 34 | delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC); |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 35 | delayacct_tsk_init(&init_task); |
| 36 | } |
| 37 | |
| 38 | void __delayacct_tsk_init(struct task_struct *tsk) |
| 39 | { |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 40 | tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL); |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 41 | if (tsk->delays) |
| 42 | spin_lock_init(&tsk->delays->lock); |
| 43 | } |
| 44 | |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 45 | /* |
| 46 | * Start accounting for a delay statistic using |
| 47 | * its starting timestamp (@start) |
| 48 | */ |
| 49 | |
| 50 | static inline void delayacct_start(struct timespec *start) |
| 51 | { |
| 52 | do_posix_clock_monotonic_gettime(start); |
| 53 | } |
| 54 | |
| 55 | /* |
| 56 | * Finish delay accounting for a statistic using |
| 57 | * its timestamps (@start, @end), accumalator (@total) and @count |
| 58 | */ |
| 59 | |
| 60 | static void delayacct_end(struct timespec *start, struct timespec *end, |
| 61 | u64 *total, u32 *count) |
| 62 | { |
| 63 | struct timespec ts; |
| 64 | s64 ns; |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 65 | unsigned long flags; |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 66 | |
| 67 | do_posix_clock_monotonic_gettime(end); |
| 68 | ts = timespec_sub(*end, *start); |
| 69 | ns = timespec_to_ns(&ts); |
| 70 | if (ns < 0) |
| 71 | return; |
| 72 | |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 73 | spin_lock_irqsave(¤t->delays->lock, flags); |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 74 | *total += ns; |
| 75 | (*count)++; |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 76 | spin_unlock_irqrestore(¤t->delays->lock, flags); |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 77 | } |
| 78 | |
Shailabh Nagar | 0ff9224 | 2006-07-14 00:24:37 -0700 | [diff] [blame] | 79 | void __delayacct_blkio_start(void) |
| 80 | { |
| 81 | delayacct_start(¤t->delays->blkio_start); |
| 82 | } |
| 83 | |
| 84 | void __delayacct_blkio_end(void) |
| 85 | { |
| 86 | if (current->delays->flags & DELAYACCT_PF_SWAPIN) |
| 87 | /* Swapin block I/O */ |
| 88 | delayacct_end(¤t->delays->blkio_start, |
| 89 | ¤t->delays->blkio_end, |
| 90 | ¤t->delays->swapin_delay, |
| 91 | ¤t->delays->swapin_count); |
| 92 | else /* Other block I/O */ |
| 93 | delayacct_end(¤t->delays->blkio_start, |
| 94 | ¤t->delays->blkio_end, |
| 95 | ¤t->delays->blkio_delay, |
| 96 | ¤t->delays->blkio_count); |
| 97 | } |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 98 | |
| 99 | int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) |
| 100 | { |
| 101 | s64 tmp; |
Balbir Singh | 172ba84 | 2007-07-09 18:52:00 +0200 | [diff] [blame] | 102 | unsigned long t1; |
| 103 | unsigned long long t2, t3; |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 104 | unsigned long flags; |
Balbir Singh | 172ba84 | 2007-07-09 18:52:00 +0200 | [diff] [blame] | 105 | struct timespec ts; |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 106 | |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 107 | /* Though tsk->delays accessed later, early exit avoids |
| 108 | * unnecessary returning of other data |
| 109 | */ |
| 110 | if (!tsk->delays) |
| 111 | goto done; |
| 112 | |
| 113 | tmp = (s64)d->cpu_run_real_total; |
| 114 | cputime_to_timespec(tsk->utime + tsk->stime, &ts); |
| 115 | tmp += timespec_to_ns(&ts); |
| 116 | d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp; |
| 117 | |
Michael Neuling | c66f08b | 2007-10-18 03:06:34 -0700 | [diff] [blame] | 118 | tmp = (s64)d->cpu_scaled_run_real_total; |
| 119 | cputime_to_timespec(tsk->utimescaled + tsk->stimescaled, &ts); |
| 120 | tmp += timespec_to_ns(&ts); |
| 121 | d->cpu_scaled_run_real_total = |
| 122 | (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp; |
| 123 | |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 124 | /* |
| 125 | * No locking available for sched_info (and too expensive to add one) |
| 126 | * Mitigate by taking snapshot of values |
| 127 | */ |
Ingo Molnar | 2d72376 | 2007-10-15 17:00:12 +0200 | [diff] [blame] | 128 | t1 = tsk->sched_info.pcount; |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 129 | t2 = tsk->sched_info.run_delay; |
| 130 | t3 = tsk->sched_info.cpu_time; |
| 131 | |
| 132 | d->cpu_count += t1; |
| 133 | |
Balbir Singh | 172ba84 | 2007-07-09 18:52:00 +0200 | [diff] [blame] | 134 | tmp = (s64)d->cpu_delay_total + t2; |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 135 | d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp; |
| 136 | |
Balbir Singh | 172ba84 | 2007-07-09 18:52:00 +0200 | [diff] [blame] | 137 | tmp = (s64)d->cpu_run_virtual_total + t3; |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 138 | d->cpu_run_virtual_total = |
| 139 | (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp; |
| 140 | |
| 141 | /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ |
| 142 | |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 143 | spin_lock_irqsave(&tsk->delays->lock, flags); |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 144 | tmp = d->blkio_delay_total + tsk->delays->blkio_delay; |
| 145 | d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp; |
| 146 | tmp = d->swapin_delay_total + tsk->delays->swapin_delay; |
| 147 | d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp; |
| 148 | d->blkio_count += tsk->delays->blkio_count; |
| 149 | d->swapin_count += tsk->delays->swapin_count; |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 150 | spin_unlock_irqrestore(&tsk->delays->lock, flags); |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 151 | |
| 152 | done: |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 153 | return 0; |
| 154 | } |
Shailabh Nagar | 2589045 | 2006-07-14 00:24:43 -0700 | [diff] [blame] | 155 | |
| 156 | __u64 __delayacct_blkio_ticks(struct task_struct *tsk) |
| 157 | { |
| 158 | __u64 ret; |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 159 | unsigned long flags; |
Shailabh Nagar | 2589045 | 2006-07-14 00:24:43 -0700 | [diff] [blame] | 160 | |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 161 | spin_lock_irqsave(&tsk->delays->lock, flags); |
Shailabh Nagar | 2589045 | 2006-07-14 00:24:43 -0700 | [diff] [blame] | 162 | ret = nsec_to_clock_t(tsk->delays->blkio_delay + |
| 163 | tsk->delays->swapin_delay); |
Peter Zijlstra | 64efade | 2006-11-05 23:52:10 -0800 | [diff] [blame] | 164 | spin_unlock_irqrestore(&tsk->delays->lock, flags); |
Shailabh Nagar | 2589045 | 2006-07-14 00:24:43 -0700 | [diff] [blame] | 165 | return ret; |
| 166 | } |
| 167 | |