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- // 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
- static 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;
- }
- static struct ctl_table kern_delayacct_table[] = {
- {
- .procname = "task_delayacct",
- .data = NULL,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = sysctl_delayacct,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- { }
- };
- static __init int kernel_delayacct_sysctls_init(void)
- {
- register_sysctl_init("kernel", kern_delayacct_table);
- return 0;
- }
- late_initcall(kernel_delayacct_sysctls_init);
- #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)
- {
- delayacct_end(&p->delays->lock,
- &p->delays->blkio_start,
- &p->delays->blkio_delay,
- &p->delays->blkio_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;
- tmp = d->compact_delay_total + tsk->delays->compact_delay;
- d->compact_delay_total = (tmp < d->compact_delay_total) ? 0 : tmp;
- tmp = d->wpcopy_delay_total + tsk->delays->wpcopy_delay;
- d->wpcopy_delay_total = (tmp < d->wpcopy_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;
- d->compact_count += tsk->delays->compact_count;
- d->wpcopy_count += tsk->delays->wpcopy_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);
- 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(bool *in_thrashing)
- {
- *in_thrashing = !!current->in_thrashing;
- if (*in_thrashing)
- return;
- current->in_thrashing = 1;
- current->delays->thrashing_start = local_clock();
- }
- void __delayacct_thrashing_end(bool *in_thrashing)
- {
- if (*in_thrashing)
- return;
- current->in_thrashing = 0;
- delayacct_end(¤t->delays->lock,
- ¤t->delays->thrashing_start,
- ¤t->delays->thrashing_delay,
- ¤t->delays->thrashing_count);
- }
- void __delayacct_swapin_start(void)
- {
- current->delays->swapin_start = local_clock();
- }
- void __delayacct_swapin_end(void)
- {
- delayacct_end(¤t->delays->lock,
- ¤t->delays->swapin_start,
- ¤t->delays->swapin_delay,
- ¤t->delays->swapin_count);
- }
- void __delayacct_compact_start(void)
- {
- current->delays->compact_start = local_clock();
- }
- void __delayacct_compact_end(void)
- {
- delayacct_end(¤t->delays->lock,
- ¤t->delays->compact_start,
- ¤t->delays->compact_delay,
- ¤t->delays->compact_count);
- }
- void __delayacct_wpcopy_start(void)
- {
- current->delays->wpcopy_start = local_clock();
- }
- void __delayacct_wpcopy_end(void)
- {
- delayacct_end(¤t->delays->lock,
- ¤t->delays->wpcopy_start,
- ¤t->delays->wpcopy_delay,
- ¤t->delays->wpcopy_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_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_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(bool *in_thrashing)
- {
- trace_android_vh_delayacct_thrashing_start(in_thrashing);
- }
- void _trace_android_vh_delayacct_thrashing_end(bool *in_thrashing)
- {
- trace_android_vh_delayacct_thrashing_end(in_thrashing);
- }
- void _trace_android_vh_delayacct_swapin_start(void)
- {
- trace_android_vh_delayacct_swapin_start(NULL);
- }
- void _trace_android_vh_delayacct_swapin_end(void)
- {
- trace_android_vh_delayacct_swapin_end(NULL);
- }
- void _trace_android_vh_delayacct_compact_start(void)
- {
- trace_android_vh_delayacct_compact_start(NULL);
- }
- void _trace_android_vh_delayacct_compact_end(void)
- {
- trace_android_vh_delayacct_compact_end(NULL);
- }
- void _trace_android_vh_delayacct_wpcopy_start(void)
- {
- trace_android_vh_delayacct_wpcopy_start(NULL);
- }
- void _trace_android_vh_delayacct_wpcopy_end(void)
- {
- trace_android_vh_delayacct_wpcopy_end(NULL);
- }
- #endif
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