| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* delayacct.c - per-task delay accounting |
| * |
| * Copyright (C) Shailabh Nagar, IBM Corp. 2006 |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/sched/task.h> |
| #include <linux/sched/cputime.h> |
| #include <linux/sched/clock.h> |
| #include <linux/slab.h> |
| #include <linux/taskstats.h> |
| #include <linux/sysctl.h> |
| #include <linux/delayacct.h> |
| #include <linux/module.h> |
| |
| #ifdef CONFIG_TASK_DELAY_ACCT |
| |
| DEFINE_STATIC_KEY_FALSE(delayacct_key); |
| int delayacct_on __read_mostly; /* Delay accounting turned on/off */ |
| struct kmem_cache *delayacct_cache; |
| |
| static void set_delayacct(bool enabled) |
| { |
| if (enabled) { |
| static_branch_enable(&delayacct_key); |
| delayacct_on = 1; |
| } else { |
| delayacct_on = 0; |
| static_branch_disable(&delayacct_key); |
| } |
| } |
| |
| static int __init delayacct_setup_enable(char *str) |
| { |
| delayacct_on = 1; |
| return 1; |
| } |
| __setup("delayacct", delayacct_setup_enable); |
| |
| void delayacct_init(void) |
| { |
| delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT); |
| delayacct_tsk_init(&init_task); |
| set_delayacct(delayacct_on); |
| } |
| |
| #ifdef CONFIG_PROC_SYSCTL |
| int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, |
| size_t *lenp, loff_t *ppos) |
| { |
| int state = delayacct_on; |
| struct ctl_table t; |
| int err; |
| |
| if (write && !capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| |
| t = *table; |
| t.data = &state; |
| err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); |
| if (err < 0) |
| return err; |
| if (write) |
| set_delayacct(state); |
| return err; |
| } |
| #endif |
| |
| void __delayacct_tsk_init(struct task_struct *tsk) |
| { |
| tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL); |
| if (tsk->delays) |
| raw_spin_lock_init(&tsk->delays->lock); |
| } |
| |
| /* |
| * Finish delay accounting for a statistic using its timestamps (@start), |
| * accumalator (@total) and @count |
| */ |
| static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total, u32 *count) |
| { |
| s64 ns = local_clock() - *start; |
| unsigned long flags; |
| |
| if (ns > 0) { |
| raw_spin_lock_irqsave(lock, flags); |
| *total += ns; |
| (*count)++; |
| raw_spin_unlock_irqrestore(lock, flags); |
| } |
| } |
| |
| void __delayacct_blkio_start(void) |
| { |
| current->delays->blkio_start = local_clock(); |
| } |
| |
| /* |
| * We cannot rely on the `current` macro, as we haven't yet switched back to |
| * the process being woken. |
| */ |
| void __delayacct_blkio_end(struct task_struct *p) |
| { |
| struct task_delay_info *delays = p->delays; |
| u64 *total; |
| u32 *count; |
| |
| if (p->delays->flags & DELAYACCT_PF_SWAPIN) { |
| total = &delays->swapin_delay; |
| count = &delays->swapin_count; |
| } else { |
| total = &delays->blkio_delay; |
| count = &delays->blkio_count; |
| } |
| |
| delayacct_end(&delays->lock, &delays->blkio_start, total, count); |
| } |
| |
| int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) |
| { |
| u64 utime, stime, stimescaled, utimescaled; |
| unsigned long long t2, t3; |
| unsigned long flags, t1; |
| s64 tmp; |
| |
| task_cputime(tsk, &utime, &stime); |
| tmp = (s64)d->cpu_run_real_total; |
| tmp += utime + stime; |
| d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp; |
| |
| task_cputime_scaled(tsk, &utimescaled, &stimescaled); |
| tmp = (s64)d->cpu_scaled_run_real_total; |
| tmp += utimescaled + stimescaled; |
| d->cpu_scaled_run_real_total = |
| (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp; |
| |
| /* |
| * No locking available for sched_info (and too expensive to add one) |
| * Mitigate by taking snapshot of values |
| */ |
| t1 = tsk->sched_info.pcount; |
| t2 = tsk->sched_info.run_delay; |
| t3 = tsk->se.sum_exec_runtime; |
| |
| d->cpu_count += t1; |
| |
| tmp = (s64)d->cpu_delay_total + t2; |
| d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp; |
| |
| tmp = (s64)d->cpu_run_virtual_total + t3; |
| d->cpu_run_virtual_total = |
| (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp; |
| |
| if (!tsk->delays) |
| return 0; |
| |
| /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ |
| |
| raw_spin_lock_irqsave(&tsk->delays->lock, flags); |
| tmp = d->blkio_delay_total + tsk->delays->blkio_delay; |
| d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp; |
| tmp = d->swapin_delay_total + tsk->delays->swapin_delay; |
| d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp; |
| tmp = d->freepages_delay_total + tsk->delays->freepages_delay; |
| d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp; |
| tmp = d->thrashing_delay_total + tsk->delays->thrashing_delay; |
| d->thrashing_delay_total = (tmp < d->thrashing_delay_total) ? 0 : tmp; |
| d->blkio_count += tsk->delays->blkio_count; |
| d->swapin_count += tsk->delays->swapin_count; |
| d->freepages_count += tsk->delays->freepages_count; |
| d->thrashing_count += tsk->delays->thrashing_count; |
| raw_spin_unlock_irqrestore(&tsk->delays->lock, flags); |
| |
| return 0; |
| } |
| |
| __u64 __delayacct_blkio_ticks(struct task_struct *tsk) |
| { |
| __u64 ret; |
| unsigned long flags; |
| |
| raw_spin_lock_irqsave(&tsk->delays->lock, flags); |
| ret = nsec_to_clock_t(tsk->delays->blkio_delay + |
| tsk->delays->swapin_delay); |
| raw_spin_unlock_irqrestore(&tsk->delays->lock, flags); |
| return ret; |
| } |
| |
| void __delayacct_freepages_start(void) |
| { |
| current->delays->freepages_start = local_clock(); |
| } |
| |
| void __delayacct_freepages_end(void) |
| { |
| delayacct_end(¤t->delays->lock, |
| ¤t->delays->freepages_start, |
| ¤t->delays->freepages_delay, |
| ¤t->delays->freepages_count); |
| } |
| |
| void __delayacct_thrashing_start(void) |
| { |
| current->delays->thrashing_start = local_clock(); |
| } |
| |
| void __delayacct_thrashing_end(void) |
| { |
| delayacct_end(¤t->delays->lock, |
| ¤t->delays->thrashing_start, |
| ¤t->delays->thrashing_delay, |
| ¤t->delays->thrashing_count); |
| } |
| #else |
| #include <trace/hooks/delayacct.h> |
| |
| int delayacct_enabled __read_mostly; /* Delay accounting turned on/off */ |
| bool get_delayacct_enabled(void) |
| { |
| return delayacct_enabled; |
| } |
| |
| void set_delayacct_enabled(bool enabled) |
| { |
| delayacct_enabled = enabled; |
| } |
| EXPORT_SYMBOL_GPL(set_delayacct_enabled); |
| |
| void _trace_android_vh_delayacct_set_flag(struct task_struct *p, int flag) |
| { |
| trace_android_vh_delayacct_set_flag(p, flag); |
| } |
| |
| void _trace_android_vh_delayacct_clear_flag(struct task_struct *p, int flag) |
| { |
| trace_android_vh_delayacct_clear_flag(p, flag); |
| } |
| |
| void _trace_android_rvh_delayacct_init(void) |
| { |
| trace_android_rvh_delayacct_init(NULL); |
| } |
| |
| void _trace_android_rvh_delayacct_tsk_init(struct task_struct *tsk) |
| { |
| trace_android_rvh_delayacct_tsk_init(tsk); |
| } |
| |
| void _trace_android_rvh_delayacct_tsk_free(struct task_struct *tsk) |
| { |
| trace_android_rvh_delayacct_tsk_free(tsk); |
| } |
| |
| void _trace_android_vh_delayacct_blkio_start(void) |
| { |
| trace_android_vh_delayacct_blkio_start(NULL); |
| } |
| |
| void _trace_android_vh_delayacct_blkio_end(struct task_struct *p) |
| { |
| trace_android_vh_delayacct_blkio_end(p); |
| } |
| |
| |
| void _trace_android_vh_delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk, int *ret) |
| { |
| trace_android_vh_delayacct_add_tsk(d, tsk, ret); |
| } |
| |
| void _trace_android_vh_delayacct_blkio_ticks(struct task_struct *tsk, __u64 *ret) |
| { |
| trace_android_vh_delayacct_blkio_ticks(tsk, ret); |
| } |
| |
| void _trace_android_vh_delayacct_is_task_waiting_on_io(struct task_struct *p, int *ret) |
| { |
| trace_android_vh_delayacct_is_task_waiting_on_io(p, ret); |
| } |
| |
| void _trace_android_vh_delayacct_freepages_start(void) |
| { |
| trace_android_vh_delayacct_freepages_start(NULL); |
| } |
| |
| void _trace_android_vh_delayacct_freepages_end(void) |
| { |
| trace_android_vh_delayacct_freepages_end(NULL); |
| } |
| |
| void _trace_android_vh_delayacct_thrashing_start(void) |
| { |
| trace_android_vh_delayacct_thrashing_start(NULL); |
| } |
| |
| void _trace_android_vh_delayacct_thrashing_end(void) |
| { |
| trace_android_vh_delayacct_thrashing_end(NULL); |
| } |
| |
| #endif |
| |