Release 4.15 kernel/time/posix-cpu-timers.c
// SPDX-License-Identifier: GPL-2.0
/*
* Implement CPU time clocks for the POSIX clock interface.
*/
#include <linux/sched/signal.h>
#include <linux/sched/cputime.h>
#include <linux/posix-timers.h>
#include <linux/errno.h>
#include <linux/math64.h>
#include <linux/uaccess.h>
#include <linux/kernel_stat.h>
#include <trace/events/timer.h>
#include <linux/tick.h>
#include <linux/workqueue.h>
#include <linux/compat.h>
#include "posix-timers.h"
static void posix_cpu_timer_rearm(struct k_itimer *timer);
/*
* Called after updating RLIMIT_CPU to run cpu timer and update
* tsk->signal->cputime_expires expiration cache if necessary. Needs
* siglock protection since other code may update expiration cache as
* well.
*/
void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
{
u64 nsecs = rlim_new * NSEC_PER_SEC;
spin_lock_irq(&task->sighand->siglock);
set_process_cpu_timer(task, CPUCLOCK_PROF, &nsecs, NULL);
spin_unlock_irq(&task->sighand->siglock);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 27 | 50.94% | 1 | 16.67% |
| Roland McGrath | 11 | 20.75% | 2 | 33.33% |
| Jiri Slaby | 8 | 15.09% | 1 | 16.67% |
| Frédéric Weisbecker | 5 | 9.43% | 1 | 16.67% |
| Stanislaw Gruszka | 2 | 3.77% | 1 | 16.67% |
| Total | 53 | 100.00% | 6 | 100.00% |
static int check_clock(const clockid_t which_clock)
{
int error = 0;
struct task_struct *p;
const pid_t pid = CPUCLOCK_PID(which_clock);
if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX)
return -EINVAL;
if (pid == 0)
return 0;
rcu_read_lock();
p = find_task_by_vpid(pid);
if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
same_thread_group(p, current) : has_group_leader_pid(p))) {
error = -EINVAL;
}
rcu_read_unlock();
return error;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 72 | 72.73% | 1 | 20.00% |
| Roland McGrath | 21 | 21.21% | 2 | 40.00% |
| Sergey Senozhatsky | 5 | 5.05% | 1 | 20.00% |
| Thomas Gleixner | 1 | 1.01% | 1 | 20.00% |
| Total | 99 | 100.00% | 5 | 100.00% |
/*
* Update expiry time from increment, and increase overrun count,
* given the current clock sample.
*/
static void bump_cpu_timer(struct k_itimer *timer, u64 now)
{
int i;
u64 delta, incr;
if (timer->it.cpu.incr == 0)
return;
if (now < timer->it.cpu.expires)
return;
incr = timer->it.cpu.incr;
delta = now + incr - timer->it.cpu.expires;
/* Don't use (incr*2 < delta), incr*2 might overflow. */
for (i = 0; incr < delta - incr; i++)
incr = incr << 1;
for (; i >= 0; incr >>= 1, i--) {
if (delta < incr)
continue;
timer->it.cpu.expires += incr;
timer->it_overrun += 1 << i;
delta -= incr;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 98 | 70.50% | 1 | 20.00% |
| Roland McGrath | 24 | 17.27% | 1 | 20.00% |
| Martin Schwidefsky | 9 | 6.47% | 1 | 20.00% |
| Frédéric Weisbecker | 8 | 5.76% | 2 | 40.00% |
| Total | 139 | 100.00% | 5 | 100.00% |
/**
* task_cputime_zero - Check a task_cputime struct for all zero fields.
*
* @cputime: The struct to compare.
*
* Checks @cputime to see if all fields are zero. Returns true if all fields
* are zero, false if any field is nonzero.
*/
static inline int task_cputime_zero(const struct task_cputime *cputime)
{
if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
return 1;
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frédéric Weisbecker | 36 | 100.00% | 2 | 100.00% |
| Total | 36 | 100.00% | 2 | 100.00% |
static inline u64 prof_ticks(struct task_struct *p)
{
u64 utime, stime;
task_cputime(p, &utime, &stime);
return utime + stime;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frédéric Weisbecker | 17 | 51.52% | 2 | 33.33% |
| Frank Mayhar | 12 | 36.36% | 1 | 16.67% |
| Roland McGrath | 3 | 9.09% | 2 | 33.33% |
| Martin Schwidefsky | 1 | 3.03% | 1 | 16.67% |
| Total | 33 | 100.00% | 6 | 100.00% |
static inline u64 virt_ticks(struct task_struct *p)
{
u64 utime, stime;
task_cputime(p, &utime, &stime);
return utime;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frédéric Weisbecker | 13 | 41.94% | 2 | 40.00% |
| Frank Mayhar | 12 | 38.71% | 1 | 20.00% |
| Stanislaw Gruszka | 4 | 12.90% | 1 | 20.00% |
| Roland McGrath | 2 | 6.45% | 1 | 20.00% |
| Total | 31 | 100.00% | 5 | 100.00% |
static int
posix_cpu_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
{
int error = check_clock(which_clock);
if (!error) {
tp->tv_sec = 0;
tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
/*
* If sched_clock is using a cycle counter, we
* don't have any idea of its true resolution
* exported, but it is much more than 1s/HZ.
*/
tp->tv_nsec = 1;
}
}
return error;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 47 | 64.38% | 1 | 16.67% |
| Roland McGrath | 23 | 31.51% | 2 | 33.33% |
| Thomas Gleixner | 2 | 2.74% | 2 | 33.33% |
| Deepa Dinamani | 1 | 1.37% | 1 | 16.67% |
| Total | 73 | 100.00% | 6 | 100.00% |
static int
posix_cpu_clock_set(const clockid_t which_clock, const struct timespec64 *tp)
{
/*
* You can never reset a CPU clock, but we check for other errors
* in the call before failing with EPERM.
*/
int error = check_clock(which_clock);
if (error == 0) {
error = -EPERM;
}
return error;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 27 | 65.85% | 1 | 20.00% |
| Frank Mayhar | 11 | 26.83% | 1 | 20.00% |
| Thomas Gleixner | 2 | 4.88% | 2 | 40.00% |
| Deepa Dinamani | 1 | 2.44% | 1 | 20.00% |
| Total | 41 | 100.00% | 5 | 100.00% |
/*
* Sample a per-thread clock for the given task.
*/
static int cpu_clock_sample(const clockid_t which_clock,
struct task_struct *p, u64 *sample)
{
switch (CPUCLOCK_WHICH(which_clock)) {
default:
return -EINVAL;
case CPUCLOCK_PROF:
*sample = prof_ticks(p);
break;
case CPUCLOCK_VIRT:
*sample = virt_ticks(p);
break;
case CPUCLOCK_SCHED:
*sample = task_sched_runtime(p);
break;
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 36 | 50.00% | 1 | 16.67% |
| Roland McGrath | 25 | 34.72% | 1 | 16.67% |
| Frédéric Weisbecker | 8 | 11.11% | 2 | 33.33% |
| Pavel Emelyanov | 2 | 2.78% | 1 | 16.67% |
| Hidetoshi Seto | 1 | 1.39% | 1 | 16.67% |
| Total | 72 | 100.00% | 6 | 100.00% |
/*
* Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg
* to avoid race conditions with concurrent updates to cputime.
*/
static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime)
{
u64 curr_cputime;
retry:
curr_cputime = atomic64_read(cputime);
if (sum_cputime > curr_cputime) {
if (atomic64_cmpxchg(cputime, curr_cputime, sum_cputime) != curr_cputime)
goto retry;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Jason Low | 50 | 100.00% | 1 | 100.00% |
| Total | 50 | 100.00% | 1 | 100.00% |
static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum)
{
__update_gt_cputime(&cputime_atomic->utime, sum->utime);
__update_gt_cputime(&cputime_atomic->stime, sum->stime);
__update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Jason Low | 36 | 69.23% | 2 | 40.00% |
| Peter Zijlstra | 14 | 26.92% | 1 | 20.00% |
| Frédéric Weisbecker | 2 | 3.85% | 2 | 40.00% |
| Total | 52 | 100.00% | 5 | 100.00% |
/* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */
static inline void sample_cputime_atomic(struct task_cputime *times,
struct task_cputime_atomic *atomic_times)
{
times->utime = atomic64_read(&atomic_times->utime);
times->stime = atomic64_read(&atomic_times->stime);
times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Jason Low | 33 | 62.26% | 2 | 50.00% |
| Peter Zijlstra | 19 | 35.85% | 1 | 25.00% |
| Frédéric Weisbecker | 1 | 1.89% | 1 | 25.00% |
| Total | 53 | 100.00% | 4 | 100.00% |
void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
struct task_cputime sum;
/* Check if cputimer isn't running. This is accessed without locking. */
if (!READ_ONCE(cputimer->running)) {
/*
* The POSIX timer interface allows for absolute time expiry
* values through the TIMER_ABSTIME flag, therefore we have
* to synchronize the timer to the clock every time we start it.
*/
thread_group_cputime(tsk, &sum);
update_gt_cputime(&cputimer->cputime_atomic, &sum);
/*
* We're setting cputimer->running without a lock. Ensure
* this only gets written to in one operation. We set
* running after update_gt_cputime() as a small optimization,
* but barriers are not required because update_gt_cputime()
* can handle concurrent updates.
*/
WRITE_ONCE(cputimer->running, true);
}
sample_cputime_atomic(times, &cputimer->cputime_atomic);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Zijlstra | 62 | 73.81% | 2 | 33.33% |
| Jason Low | 19 | 22.62% | 3 | 50.00% |
| Frédéric Weisbecker | 3 | 3.57% | 1 | 16.67% |
| Total | 84 | 100.00% | 6 | 100.00% |
/*
* Sample a process (thread group) clock for the given group_leader task.
* Must be called with task sighand lock held for safe while_each_thread()
* traversal.
*/
static int cpu_clock_sample_group(const clockid_t which_clock,
struct task_struct *p,
u64 *sample)
{
struct task_cputime cputime;
switch (CPUCLOCK_WHICH(which_clock)) {
default:
return -EINVAL;
case CPUCLOCK_PROF:
thread_group_cputime(p, &cputime);
*sample = cputime.utime + cputime.stime;
break;
case CPUCLOCK_VIRT:
thread_group_cputime(p, &cputime);
*sample = cputime.utime;
break;
case CPUCLOCK_SCHED:
thread_group_cputime(p, &cputime);
*sample = cputime.sum_exec_runtime;
break;
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 39 | 38.61% | 2 | 22.22% |
| Roland McGrath | 22 | 21.78% | 1 | 11.11% |
| Hidetoshi Seto | 14 | 13.86% | 1 | 11.11% |
| Frédéric Weisbecker | 12 | 11.88% | 2 | 22.22% |
| Peter Zijlstra | 10 | 9.90% | 1 | 11.11% |
| Petr Tesarik | 3 | 2.97% | 1 | 11.11% |
| Martin Schwidefsky | 1 | 0.99% | 1 | 11.11% |
| Total | 101 | 100.00% | 9 | 100.00% |
static int posix_cpu_clock_get_task(struct task_struct *tsk,
const clockid_t which_clock,
struct timespec64 *tp)
{
int err = -EINVAL;
u64 rtn;
if (CPUCLOCK_PERTHREAD(which_clock)) {
if (same_thread_group(tsk, current))
err = cpu_clock_sample(which_clock, tsk, &rtn);
} else {
if (tsk == current || thread_group_leader(tsk))
err = cpu_clock_sample_group(which_clock, tsk, &rtn);
}
if (!err)
*tp = ns_to_timespec64(rtn);
return err;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frédéric Weisbecker | 42 | 41.58% | 3 | 33.33% |
| Frank Mayhar | 36 | 35.64% | 1 | 11.11% |
| Roland McGrath | 11 | 10.89% | 1 | 11.11% |
| Oleg Nesterov | 6 | 5.94% | 1 | 11.11% |
| Linus Torvalds | 3 | 2.97% | 1 | 11.11% |
| Deepa Dinamani | 2 | 1.98% | 1 | 11.11% |
| Thomas Gleixner | 1 | 0.99% | 1 | 11.11% |
| Total | 101 | 100.00% | 9 | 100.00% |
static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec64 *tp)
{
const pid_t pid = CPUCLOCK_PID(which_clock);
int err = -EINVAL;
if (pid == 0) {
/*
* Special case constant value for our own clocks.
* We don't have to do any lookup to find ourselves.
*/
err = posix_cpu_clock_get_task(current, which_clock, tp);
} else {
/*
* Find the given PID, and validate that the caller
* should be able to see it.
*/
struct task_struct *p;
rcu_read_lock();
p = find_task_by_vpid(pid);
if (p)
err = posix_cpu_clock_get_task(p, which_clock, tp);
rcu_read_unlock();
}
return err;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frédéric Weisbecker | 55 | 61.11% | 1 | 16.67% |
| Frank Mayhar | 25 | 27.78% | 1 | 16.67% |
| Roland McGrath | 6 | 6.67% | 1 | 16.67% |
| Linus Torvalds | 2 | 2.22% | 1 | 16.67% |
| Oleg Nesterov | 1 | 1.11% | 1 | 16.67% |
| Deepa Dinamani | 1 | 1.11% | 1 | 16.67% |
| Total | 90 | 100.00% | 6 | 100.00% |
/*
* Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
* This is called from sys_timer_create() and do_cpu_nanosleep() with the
* new timer already all-zeros initialized.
*/
static int posix_cpu_timer_create(struct k_itimer *new_timer)
{
int ret = 0;
const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
struct task_struct *p;
if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
return -EINVAL;
new_timer->kclock = &clock_posix_cpu;
INIT_LIST_HEAD(&new_timer->it.cpu.entry);
rcu_read_lock();
if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
if (pid == 0) {
p = current;
} else {
p = find_task_by_vpid(pid);
if (p && !same_thread_group(p, current))
p = NULL;
}
} else {
if (pid == 0) {
p = current->group_leader;
} else {
p = find_task_by_vpid(pid);
if (p && !has_group_leader_pid(p))
p = NULL;
}
}
new_timer->it.cpu.task = p;
if (p) {
get_task_struct(p);
} else {
ret = -EINVAL;
}
rcu_read_unlock();
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 115 | 59.28% | 1 | 20.00% |
| Roland McGrath | 66 | 34.02% | 1 | 20.00% |
| Thomas Gleixner | 8 | 4.12% | 2 | 40.00% |
| Sergey Senozhatsky | 5 | 2.58% | 1 | 20.00% |
| Total | 194 | 100.00% | 5 | 100.00% |
/*
* Clean up a CPU-clock timer that is about to be destroyed.
* This is called from timer deletion with the timer already locked.
* If we return TIMER_RETRY, it's necessary to release the timer's lock
* and try again. (This happens when the timer is in the middle of firing.)
*/
static int posix_cpu_timer_del(struct k_itimer *timer)
{
int ret = 0;
unsigned long flags;
struct sighand_struct *sighand;
struct task_struct *p = timer->it.cpu.task;
WARN_ON_ONCE(p == NULL);
/*
* Protect against sighand release/switch in exit/exec and process/
* thread timer list entry concurrent read/writes.
*/
sighand = lock_task_sighand(p, &flags);
if (unlikely(sighand == NULL)) {
/*
* We raced with the reaping of the task.
* The deletion should have cleared us off the list.
*/
WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry));
} else {
if (timer->it.cpu.firing)
ret = TIMER_RETRY;
else
list_del(&timer->it.cpu.entry);
unlock_task_sighand(p, &flags);
}
if (!ret)
put_task_struct(p);
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 86 | 63.70% | 1 | 12.50% |
| Frédéric Weisbecker | 30 | 22.22% | 3 | 37.50% |
| Roland McGrath | 16 | 11.85% | 1 | 12.50% |
| Ingo Molnar | 1 | 0.74% | 1 | 12.50% |
| Thomas Gleixner | 1 | 0.74% | 1 | 12.50% |
| Oleg Nesterov | 1 | 0.74% | 1 | 12.50% |
| Total | 135 | 100.00% | 8 | 100.00% |
static void cleanup_timers_list(struct list_head *head)
{
struct cpu_timer_list *timer, *next;
list_for_each_entry_safe(timer, next, head, entry)
list_del_init(&timer->entry);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 19 | 51.35% | 1 | 20.00% |
| Roland McGrath | 14 | 37.84% | 2 | 40.00% |
| Martin Schwidefsky | 2 | 5.41% | 1 | 20.00% |
| Frédéric Weisbecker | 2 | 5.41% | 1 | 20.00% |
| Total | 37 | 100.00% | 5 | 100.00% |
/*
* Clean out CPU timers still ticking when a thread exited. The task
* pointer is cleared, and the expiry time is replaced with the residual
* time for later timer_gettime calls to return.
* This must be called with the siglock held.
*/
static void cleanup_timers(struct list_head *head)
{
cleanup_timers_list(head);
cleanup_timers_list(++head);
cleanup_timers_list(++head);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frédéric Weisbecker | 19 | 67.86% | 2 | 50.00% |
| Roland McGrath | 5 | 17.86% | 1 | 25.00% |
| Frank Mayhar | 4 | 14.29% | 1 | 25.00% |
| Total | 28 | 100.00% | 4 | 100.00% |
/*
* These are both called with the siglock held, when the current thread
* is being reaped. When the final (leader) thread in the group is reaped,
* posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit.
*/
void posix_cpu_timers_exit(struct task_struct *tsk)
{
cleanup_timers(tsk->cpu_timers);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 13 | 76.47% | 1 | 50.00% |
| Roland McGrath | 4 | 23.53% | 1 | 50.00% |
| Total | 17 | 100.00% | 2 | 100.00% |
void posix_cpu_timers_exit_group(struct task_struct *tsk)
{
cleanup_timers(tsk->signal->cpu_timers);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 18 | 94.74% | 1 | 50.00% |
| Roland McGrath | 1 | 5.26% | 1 | 50.00% |
| Total | 19 | 100.00% | 2 | 100.00% |
static inline int expires_gt(u64 expires, u64 new_exp)
{
return expires == 0 || expires > new_exp;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Stanislaw Gruszka | 17 | 77.27% | 1 | 33.33% |
| Martin Schwidefsky | 3 | 13.64% | 1 | 33.33% |
| Frédéric Weisbecker | 2 | 9.09% | 1 | 33.33% |
| Total | 22 | 100.00% | 3 | 100.00% |
/*
* Insert the timer on the appropriate list before any timers that
* expire later. This must be called with the sighand lock held.
*/
static void arm_timer(struct k_itimer *timer)
{
struct task_struct *p = timer->it.cpu.task;
struct list_head *head, *listpos;
struct task_cputime *cputime_expires;
struct cpu_timer_list *const nt = &timer->it.cpu;
struct cpu_timer_list *next;
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
head = p->cpu_timers;
cputime_expires = &p->cputime_expires;
} else {
head = p->signal->cpu_timers;
cputime_expires = &p->signal->cputime_expires;
}
head += CPUCLOCK_WHICH(timer->it_clock);
listpos = head;
list_for_each_entry(next, head, entry) {
if (nt->expires < next->expires)
break;
listpos = &next->entry;
}
list_add(&nt->entry, listpos);
if (listpos == head) {
u64 exp = nt->expires;
/*
* We are the new earliest-expiring POSIX 1.b timer, hence
* need to update expiration cache. Take into account that
* for process timers we share expiration cache with itimers
* and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
*/
switch (CPUCLOCK_WHICH(timer->it_clock)) {
case CPUCLOCK_PROF:
if (expires_gt(cputime_expires->prof_exp, exp))
cputime_expires->prof_exp = exp;
break;
case CPUCLOCK_VIRT:
if (expires_gt(cputime_expires->virt_exp, exp))
cputime_expires->virt_exp = exp;
break;
case CPUCLOCK_SCHED:
if (expires_gt(cputime_expires->sched_exp, exp))
cputime_expires->sched_exp = exp;
break;
}
if (CPUCLOCK_PERTHREAD(timer->it_clock))
tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER);
else
tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 140 | 52.63% | 2 | 18.18% |
| Stanislaw Gruszka | 53 | 19.92% | 3 | 27.27% |
| Frédéric Weisbecker | 35 | 13.16% | 3 | 27.27% |
| Martin Schwidefsky | 23 | 8.65% | 1 | 9.09% |
| Frank Mayhar | 14 | 5.26% | 1 | 9.09% |
| Linus Torvalds | 1 | 0.38% | 1 | 9.09% |
| Total | 266 | 100.00% | 11 | 100.00% |
/*
* The timer is locked, fire it and arrange for its reload.
*/
static void cpu_timer_fire(struct k_itimer *timer)
{
if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
/*
* User don't want any signal.
*/
timer->it.cpu.expires = 0;
} else if (unlikely(timer->sigq == NULL)) {
/*
* This a special case for clock_nanosleep,
* not a normal timer from sys_timer_create.
*/
wake_up_process(timer->it_process);
timer->it.cpu.expires = 0;
} else if (timer->it.cpu.incr == 0) {
/*
* One-shot timer. Clear it as soon as it's fired.
*/
posix_timer_event(timer, 0);
timer->it.cpu.expires = 0;
} else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
/*
* The signal did not get queued because the signal
* was ignored, so we won't get any callback to
* reload the timer. But we need to keep it
* ticking in case the signal is deliverable next time.
*/
posix_cpu_timer_rearm(timer);
++timer->it_requeue_pending;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 95 | 74.22% | 2 | 40.00% |
| Stanislaw Gruszka | 27 | 21.09% | 1 | 20.00% |
| Thomas Gleixner | 6 | 4.69% | 2 | 40.00% |
| Total | 128 | 100.00% | 5 | 100.00% |
/*
* Sample a process (thread group) timer for the given group_leader task.
* Must be called with task sighand lock held for safe while_each_thread()
* traversal.
*/
static int cpu_timer_sample_group(const clockid_t which_clock,
struct task_struct *p, u64 *sample)
{
struct task_cputime cputime;
thread_group_cputimer(p, &cputime);
switch (CPUCLOCK_WHICH(which_clock)) {
default:
return -EINVAL;
case CPUCLOCK_PROF:
*sample = cputime.utime + cputime.stime;
break;
case CPUCLOCK_VIRT:
*sample = cputime.utime;
break;
case CPUCLOCK_SCHED:
*sample = cputime.sum_exec_runtime;
break;
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Zijlstra | 75 | 88.24% | 1 | 25.00% |
| Frédéric Weisbecker | 9 | 10.59% | 2 | 50.00% |
| Martin Schwidefsky | 1 | 1.18% | 1 | 25.00% |
| Total | 85 | 100.00% | 4 | 100.00% |
/*
* Guts of sys_timer_settime for CPU timers.
* This is called with the timer locked and interrupts disabled.
* If we return TIMER_RETRY, it's necessary to release the timer's lock
* and try again. (This happens when the timer is in the middle of firing.)
*/
static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
struct itimerspec64 *new, struct itimerspec64 *old)
{
unsigned long flags;
struct sighand_struct *sighand;
struct task_struct *p = timer->it.cpu.task;
u64 old_expires, new_expires, old_incr, val;
int ret;
WARN_ON_ONCE(p == NULL);
/*
* Use the to_ktime conversion because that clamps the maximum
* value to KTIME_MAX and avoid multiplication overflows.
*/
new_expires = ktime_to_ns(timespec64_to_ktime(new->it_value));
/*
* Protect against sighand release/switch in exit/exec and p->cpu_timers
* and p->signal->cpu_timers read/write in arm_timer()
*/
sighand = lock_task_sighand(p, &flags);
/*
* If p has just been reaped, we can no
* longer get any information about it at all.
*/
if (unlikely(sighand == NULL)) {
return -ESRCH;
}
/*
* Disarm any old timer after extracting its expiry time.
*/
lockdep_assert_irqs_disabled();
ret = 0;
old_incr = timer->it.cpu.incr;
old_expires = timer->it.cpu.expires;
if (unlikely(timer->it.cpu.firing)) {
timer->it.cpu.firing = -1;
ret = TIMER_RETRY;
} else
list_del_init(&timer->it.cpu.entry);
/*
* We need to sample the current value to convert the new
* value from to relative and absolute, and to convert the
* old value from absolute to relative. To set a process
* timer, we need a sample to balance the thread expiry
* times (in arm_timer). With an absolute time, we must
* check if it's already passed. In short, we need a sample.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
cpu_clock_sample(timer->it_clock, p, &val);
} else {
cpu_timer_sample_group(timer->it_clock, p, &val);
}
if (old) {
if (old_expires == 0) {
old->it_value.tv_sec = 0;
old->it_value.tv_nsec = 0;
} else {
/*
* Update the timer in case it has
* overrun already. If it has,
* we'll report it as having overrun
* and with the next reloaded timer
* already ticking, though we are
* swallowing that pending
* notification here to install the
* new setting.
*/
bump_cpu_timer(timer, val);
if (val < timer->it.cpu.expires) {
old_expires = timer->it.cpu.expires - val;
old->it_value = ns_to_timespec64(old_expires);
} else {
old->it_value.tv_nsec = 1;
old->it_value.tv_sec = 0;
}
}
}
if (unlikely(ret)) {
/*
* We are colliding with the timer actually firing.
* Punt after filling in the timer's old value, and
* disable this firing since we are already reporting
* it as an overrun (thanks to bump_cpu_timer above).
*/
unlock_task_sighand(p, &flags);
goto out;
}
if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) {
new_expires += val;
}
/*
* Install the new expiry time (or zero).
* For a timer with no notification action, we don't actually
* arm the timer (we'll just fake it for timer_gettime).
*/
timer->it.cpu.expires = new_expires;
if (new_expires != 0 && val < new_expires) {
arm_timer(timer);
}
unlock_task_sighand(p, &flags);
/*
* Install the new reload setting, and
* set up the signal and overrun bookkeeping.
*/
timer->it.cpu.incr = timespec64_to_ns(&new->it_interval);
/*
* This acts as a modification timestamp for the timer,
* so any automatic reload attempt will punt on seeing
* that we have reset the timer manually.
*/
timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
~REQUEUE_PENDING;
timer->it_overrun_last = 0;
timer->it_overrun = -1;
if (new_expires != 0 && !(val < new_expires)) {
/*
* The designated time already passed, so we notify
* immediately, even if the thread never runs to
* accumulate more time on this clock.
*/
cpu_timer_fire(timer);
}
ret = 0;
out:
if (old)
old->it_interval = ns_to_timespec64(old_incr);
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 368 | 77.47% | 1 | 7.14% |
| Frédéric Weisbecker | 42 | 8.84% | 5 | 35.71% |
| Oleg Nesterov | 37 | 7.79% | 2 | 14.29% |
| Stanislaw Gruszka | 16 | 3.37% | 2 | 14.29% |
| Thomas Gleixner | 6 | 1.26% | 2 | 14.29% |
| Deepa Dinamani | 5 | 1.05% | 1 | 7.14% |
| Peter Zijlstra | 1 | 0.21% | 1 | 7.14% |
| Total | 475 | 100.00% | 14 | 100.00% |
static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp)
{
u64 now;
struct task_struct *p = timer->it.cpu.task;
WARN_ON_ONCE(p == NULL);
/*
* Easy part: convert the reload time.
*/
itp->it_interval = ns_to_timespec64(timer->it.cpu.incr);
if (!timer->it.cpu.expires)
return;
/*
* Sample the clock to take the difference with the expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
cpu_clock_sample(timer->it_clock, p, &now);
} else {
struct sighand_struct *sighand;
unsigned long flags;
/*
* Protect against sighand release/switch in exit/exec and
* also make timer sampling safe if it ends up calling
* thread_group_cputime().
*/
sighand = lock_task_sighand(p, &flags);
if (unlikely(sighand == NULL)) {
/*
* The process has been reaped.
* We can't even collect a sample any more.
* Call the timer disarmed, nothing else to do.
*/
timer->it.cpu.expires = 0;
return;
} else {
cpu_timer_sample_group(timer->it_clock, p, &now);
unlock_task_sighand(p, &flags);
}
}
if (now < timer->it.cpu.expires) {
itp->it_value = ns_to_timespec64(timer->it.cpu.expires - now);
} else {
/*
* The timer should have expired already, but the firing
* hasn't taken place yet. Say it's just about to expire.
*/
itp->it_value.tv_nsec = 1;
itp->it_value.tv_sec = 0;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 159 | 75.36% | 1 | 8.33% |
| Frédéric Weisbecker | 44 | 20.85% | 5 | 41.67% |
| Deepa Dinamani | 3 | 1.42% | 1 | 8.33% |
| Thomas Gleixner | 2 | 0.95% | 2 | 16.67% |
| Peter Zijlstra | 1 | 0.47% | 1 | 8.33% |
| Oleg Nesterov | 1 | 0.47% | 1 | 8.33% |
| Alexey Dobriyan | 1 | 0.47% | 1 | 8.33% |
| Total | 211 | 100.00% | 12 | 100.00% |
static unsigned long long
check_timers_list(struct list_head *timers,
struct list_head *firing,
unsigned long long curr)
{
int maxfire = 20;
while (!list_empty(timers)) {
struct cpu_timer_list *t;
t = list_first_entry(timers, struct cpu_timer_list, entry);
if (!--maxfire || curr < t->expires)
return t->expires;
t->firing = 1;
list_move_tail(&t->entry, firing);
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 58 | 63.74% | 1 | 16.67% |
| Frédéric Weisbecker | 23 | 25.27% | 1 | 16.67% |
| Linus Torvalds | 7 | 7.69% | 1 | 16.67% |
| Martin Schwidefsky | 1 | 1.10% | 1 | 16.67% |
| Peter Zijlstra | 1 | 1.10% | 1 | 16.67% |
| Pavel Emelyanov | 1 | 1.10% | 1 | 16.67% |
| Total | 91 | 100.00% | 6 | 100.00% |
/*
* Check for any per-thread CPU timers that have fired and move them off
* the tsk->cpu_timers[N] list onto the firing list. Here we update the
* tsk->it_*_expires values to reflect the remaining thread CPU timers.
*/
static void check_thread_timers(struct task_struct *tsk,
struct list_head *firing)
{
struct list_head *timers = tsk->cpu_timers;
struct task_cputime *tsk_expires = &tsk->cputime_expires;
u64 expires;
unsigned long soft;
/*
* If cputime_expires is zero, then there are no active
* per thread CPU timers.
*/
if (task_cputime_zero(&tsk->cputime_expires))
return;
expires = check_timers_list(timers, firing, prof_ticks(tsk));
tsk_expires->prof_exp = expires;
expires = check_timers_list(++timers, firing, virt_ticks(tsk));
tsk_expires->virt_exp = expires;
tsk_expires->sched_exp = check_timers_list(++timers, firing,
tsk->se.sum_exec_runtime);
/*
* Check for the special case thread timers.
*/
soft = task_rlimit(tsk, RLIMIT_RTTIME);
if (soft != RLIM_INFINITY) {
unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME);
if (hard != RLIM_INFINITY &&
tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
/*
* At the hard limit, we just die.
* No need to calculate anything else now.
*/
if (print_fatal_signals) {
pr_info("CPU Watchdog Timeout (hard): %s[%d]\n",
tsk->comm, task_pid_nr(tsk));
}
__group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
return;
}
if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
/*
* At the soft limit, send a SIGXCPU every second.
*/
if (soft < hard) {
soft += USEC_PER_SEC;
tsk->signal->rlim[RLIMIT_RTTIME].rlim_cur =
soft;
}
if (print_fatal_signals) {
pr_info("RT Watchdog Timeout (soft): %s[%d]\n",
tsk->comm, task_pid_nr(tsk));
}
__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
}
}
if (task_cputime_zero(tsk_expires))
tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Zijlstra | 90 | 31.69% | 2 | 12.50% |
| Frédéric Weisbecker | 77 | 27.11% | 3 | 18.75% |
| Roland McGrath | 32 | 11.27% | 1 | 6.25% |
| Jiri Slaby | 18 | 6.34% | 2 | 12.50% |
| Arun Raghavan | 16 | 5.63% | 1 | 6.25% |
| Thomas Gleixner | 12 | 4.23% | 1 | 6.25% |
| Hiroshi Shimamoto | 12 | 4.23% | 1 | 6.25% |
| Jason Low | 12 | 4.23% | 1 | 6.25% |
| Krzysztof Opasiak | 9 | 3.17% | 1 | 6.25% |
| Ingo Molnar | 3 | 1.06% | 1 | 6.25% |
| Linus Torvalds | 2 | 0.70% | 1 | 6.25% |
| Frank Mayhar | 1 | 0.35% | 1 | 6.25% |
| Total | 284 | 100.00% | 16 | 100.00% |
static inline void stop_process_timers(struct signal_struct *sig)
{
struct thread_group_cputimer *cputimer = &sig->cputimer;
/* Turn off cputimer->running. This is done without locking. */
WRITE_ONCE(cputimer->running, false);
tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Zijlstra | 25 | 64.10% | 1 | 20.00% |
| Frédéric Weisbecker | 7 | 17.95% | 1 | 20.00% |
| Jason Low | 4 | 10.26% | 2 | 40.00% |
| Stanislaw Gruszka | 3 | 7.69% | 1 | 20.00% |
| Total | 39 | 100.00% | 5 | 100.00% |
static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
u64 *expires, u64 cur_time, int signo)
{
if (!it->expires)
return;
if (cur_time >= it->expires) {
if (it->incr)
it->expires += it->incr;
else
it->expires = 0;
trace_itimer_expire(signo == SIGPROF ?
ITIMER_PROF : ITIMER_VIRTUAL,
tsk->signal->leader_pid, cur_time);
__group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
}
if (it->expires && (!*expires || it->expires < *expires))
*expires = it->expires;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Stanislaw Gruszka | 92 | 77.31% | 2 | 40.00% |
| Xiao Guangrong | 19 | 15.97% | 1 | 20.00% |
| Martin Schwidefsky | 6 | 5.04% | 1 | 20.00% |
| Frédéric Weisbecker | 2 | 1.68% | 1 | 20.00% |
| Total | 119 | 100.00% | 5 | 100.00% |
/*
* Check for any per-thread CPU timers that have fired and move them
* off the tsk->*_timers list onto the firing list. Per-thread timers
* have already been taken off.
*/
static void check_process_timers(struct task_struct *tsk,
struct list_head *firing)
{
struct signal_struct *const sig = tsk->signal;
u64 utime, ptime, virt_expires, prof_expires;
u64 sum_sched_runtime, sched_expires;
struct list_head *timers = sig->cpu_timers;
struct task_cputime cputime;
unsigned long soft;
/*
* If cputimer is not running, then there are no active
* process wide timers (POSIX 1.b, itimers, RLIMIT_CPU).
*/
if (!READ_ONCE(tsk->signal->cputimer.running))
return;
/*
* Signify that a thread is checking for process timers.
* Write access to this field is protected by the sighand lock.
*/
sig->cputimer.checking_timer = true;
/*
* Collect the current process totals.
*/
thread_group_cputimer(tsk, &cputime);
utime = cputime.utime;
ptime = utime + cputime.stime;
sum_sched_runtime = cputime.sum_exec_runtime;
prof_expires = check_timers_list(timers, firing, ptime);
virt_expires = check_timers_list(++timers, firing, utime);
sched_expires = check_timers_list(++timers, firing, sum_sched_runtime);
/*
* Check for the special case process timers.
*/
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
SIGPROF);
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
SIGVTALRM);
soft = task_rlimit(tsk, RLIMIT_CPU);
if (soft != RLIM_INFINITY) {
unsigned long psecs = div_u64(ptime, NSEC_PER_SEC);
unsigned long hard = task_rlimit_max(tsk, RLIMIT_CPU);
u64 x;
if (psecs >= hard) {
/*
* At the hard limit, we just die.
* No need to calculate anything else now.
*/
if (print_fatal_signals) {
pr_info("RT Watchdog Timeout (hard): %s[%d]\n",
tsk->comm, task_pid_nr(tsk));
}
__group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
return;
}
if (psecs >= soft) {
/*
* At the soft limit, send a SIGXCPU every second.
*/
if (print_fatal_signals) {
pr_info("CPU Watchdog Timeout (soft): %s[%d]\n",
tsk->comm, task_pid_nr(tsk));
}
__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
if (soft < hard) {
soft++;
sig->rlim[RLIMIT_CPU].rlim_cur = soft;
}
}
x = soft * NSEC_PER_SEC;
if (!prof_expires || x < prof_expires)
prof_expires = x;
}
sig->cputime_expires.prof_exp = prof_expires;
sig->cputime_expires.virt_exp = virt_expires;
sig->cputime_expires.sched_exp = sched_expires;
if (task_cputime_zero(&sig->cputime_expires))
stop_process_timers(sig);
sig->cputimer.checking_timer = false;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 178 | 45.18% | 4 | 20.00% |
| Frank Mayhar | 45 | 11.42% | 1 | 5.00% |
| Jiri Slaby | 35 | 8.88% | 2 | 10.00% |
| Jason Low | 33 | 8.38% | 2 | 10.00% |
| Stanislaw Gruszka | 30 | 7.61% | 2 | 10.00% |
| Arun Raghavan | 28 | 7.11% | 1 | 5.00% |
| Frédéric Weisbecker | 17 | 4.31% | 2 | 10.00% |
| Thomas Gleixner | 13 | 3.30% | 2 | 10.00% |
| Krzysztof Opasiak | 6 | 1.52% | 1 | 5.00% |
| Ingo Molnar | 5 | 1.27% | 1 | 5.00% |
| Martin Schwidefsky | 3 | 0.76% | 1 | 5.00% |
| Peter Zijlstra | 1 | 0.25% | 1 | 5.00% |
| Total | 394 | 100.00% | 20 | 100.00% |
/*
* This is called from the signal code (via posixtimer_rearm)
* when the last timer signal was delivered and we have to reload the timer.
*/
static void posix_cpu_timer_rearm(struct k_itimer *timer)
{
struct sighand_struct *sighand;
unsigned long flags;
struct task_struct *p = timer->it.cpu.task;
u64 now;
WARN_ON_ONCE(p == NULL);
/*
* Fetch the current sample and update the timer's expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
cpu_clock_sample(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
if (unlikely(p->exit_state))
return;
/* Protect timer list r/w in arm_timer() */
sighand = lock_task_sighand(p, &flags);
if (!sighand)
return;
} else {
/*
* Protect arm_timer() and timer sampling in case of call to
* thread_group_cputime().
*/
sighand = lock_task_sighand(p, &flags);
if (unlikely(sighand == NULL)) {
/*
* The process has been reaped.
* We can't even collect a sample any more.
*/
timer->it.cpu.expires = 0;
return;
} else if (unlikely(p->exit_state) && thread_group_empty(p)) {
/* If the process is dying, no need to rearm */
goto unlock;
}
cpu_timer_sample_group(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
/* Leave the sighand locked for the call below. */
}
/*
* Now re-arm for the new expiry time.
*/
lockdep_assert_irqs_disabled();
arm_timer(timer);
unlock:
unlock_task_sighand(p, &flags);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 91 | 45.96% | 1 | 8.33% |
| Roland McGrath | 56 | 28.28% | 1 | 8.33% |
| Frédéric Weisbecker | 35 | 17.68% | 5 | 41.67% |
| Thomas Gleixner | 9 | 4.55% | 2 | 16.67% |
| Stanislaw Gruszka | 5 | 2.53% | 1 | 8.33% |
| Peter Zijlstra | 1 | 0.51% | 1 | 8.33% |
| Oleg Nesterov | 1 | 0.51% | 1 | 8.33% |
| Total | 198 | 100.00% | 12 | 100.00% |
/**
* task_cputime_expired - Compare two task_cputime entities.
*
* @sample: The task_cputime structure to be checked for expiration.
* @expires: Expiration times, against which @sample will be checked.
*
* Checks @sample against @expires to see if any field of @sample has expired.
* Returns true if any field of the former is greater than the corresponding
* field of the latter if the latter field is set. Otherwise returns false.
*/
static inline int task_cputime_expired(const struct task_cputime *sample,
const struct task_cputime *expires)
{
if (expires->utime && sample->utime >= expires->utime)
return 1;
if (expires->stime && sample->utime + sample->stime >= expires->stime)
return 1;
if (expires->sum_exec_runtime != 0 &&
sample->sum_exec_runtime >= expires->sum_exec_runtime)
return 1;
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 69 | 87.34% | 1 | 25.00% |
| Roland McGrath | 5 | 6.33% | 1 | 25.00% |
| Martin Schwidefsky | 3 | 3.80% | 1 | 25.00% |
| Frédéric Weisbecker | 2 | 2.53% | 1 | 25.00% |
| Total | 79 | 100.00% | 4 | 100.00% |
/**
* fastpath_timer_check - POSIX CPU timers fast path.
*
* @tsk: The task (thread) being checked.
*
* Check the task and thread group timers. If both are zero (there are no
* timers set) return false. Otherwise snapshot the task and thread group
* timers and compare them with the corresponding expiration times. Return
* true if a timer has expired, else return false.
*/
static inline int fastpath_timer_check(struct task_struct *tsk)
{
struct signal_struct *sig;
if (!task_cputime_zero(&tsk->cputime_expires)) {
struct task_cputime task_sample;
task_cputime(tsk, &task_sample.utime, &task_sample.stime);
task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime;
if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
return 1;
}
sig = tsk->signal;
/*
* Check if thread group timers expired when the cputimer is
* running and no other thread in the group is already checking
* for thread group cputimers. These fields are read without the
* sighand lock. However, this is fine because this is meant to
* be a fastpath heuristic to determine whether we should try to
* acquire the sighand lock to check/handle timers.
*
* In the worst case scenario, if 'running' or 'checking_timer' gets
* set but the current thread doesn't see the change yet, we'll wait
* until the next thread in the group gets a scheduler interrupt to
* handle the timer. This isn't an issue in practice because these
* types of delays with signals actually getting sent are expected.
*/
if (READ_ONCE(sig->cputimer.running) &&
!READ_ONCE(sig->cputimer.checking_timer)) {
struct task_cputime group_sample;
sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic);
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Frank Mayhar | 76 | 53.90% | 2 | 14.29% |
| Jason Low | 31 | 21.99% | 4 | 28.57% |
| Roland McGrath | 17 | 12.06% | 3 | 21.43% |
| Oleg Nesterov | 10 | 7.09% | 2 | 14.29% |
| Stanislaw Gruszka | 4 | 2.84% | 2 | 14.29% |
| Frédéric Weisbecker | 3 | 2.13% | 1 | 7.14% |
| Total | 141 | 100.00% | 14 | 100.00% |
/*
* This is called from the timer interrupt handler. The irq handler has
* already updated our counts. We need to check if any timers fire now.
* Interrupts are disabled.
*/
void run_posix_cpu_timers(struct task_struct *tsk)
{
LIST_HEAD(firing);
struct k_itimer *timer, *next;
unsigned long flags;
lockdep_assert_irqs_disabled();
/*
* The fast path checks that there are no expired thread or thread
* group timers. If that's so, just return.
*/
if (!fastpath_timer_check(tsk))
return;
if (!lock_task_sighand(tsk, &flags))
return;
/*
* Here we take off tsk->signal->cpu_timers[N] and
* tsk->cpu_timers[N] all the timers that are firing, and
* put them on the firing list.
*/
check_thread_timers(tsk, &firing);
check_process_timers(tsk, &firing);
/*
* We must release these locks before taking any timer's lock.
* There is a potential race with timer deletion here, as the
* siglock now protects our private firing list. We have set
* the firing flag in each timer, so that a deletion attempt
* that gets the timer lock before we do will give it up and
* spin until we've taken care of that timer below.
*/
unlock_task_sighand(tsk, &flags);
/*
* Now that all the timers on our list have the firing flag,
* no one will touch their list entries but us. We'll take
* each timer's lock before clearing its firing flag, so no
* timer call will interfere.
*/
list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
int cpu_firing;
spin_lock(&timer->it_lock);
list_del_init(&timer->it.cpu.entry);
cpu_firing = timer->it.cpu.firing;
timer->it.cpu.firing = 0;
/*
* The firing flag is -1 if we collided with a reset
* of the timer, which already reported this
* almost-firing as an overrun. So don't generate an event.
*/
if (likely(cpu_firing >= 0))
cpu_timer_fire(timer);
spin_unlock(&timer->it_lock);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 125 | 79.62% | 2 | 22.22% |
| Oleg Nesterov | 18 | 11.46% | 2 | 22.22% |
| Frank Mayhar | 9 | 5.73% | 2 | 22.22% |
| H Hartley Sweeten | 3 | 1.91% | 1 | 11.11% |
| Frédéric Weisbecker | 1 | 0.64% | 1 | 11.11% |
| Lucas De Marchi | 1 | 0.64% | 1 | 11.11% |
| Total | 157 | 100.00% | 9 | 100.00% |
/*
* Set one of the process-wide special case CPU timers or RLIMIT_CPU.
* The tsk->sighand->siglock must be held by the caller.
*/
void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
u64 *newval, u64 *oldval)
{
u64 now;
WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED);
cpu_timer_sample_group(clock_idx, tsk, &now);
if (oldval) {
/*
* We are setting itimer. The *oldval is absolute and we update
* it to be relative, *newval argument is relative and we update
* it to be absolute.
*/
if (*oldval) {
if (*oldval <= now) {
/* Just about to fire. */
*oldval = TICK_NSEC;
} else {
*oldval -= now;
}
}
if (!*newval)
return;
*newval += now;
}
/*
* Update expiration cache if we are the earliest timer, or eventually
* RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
*/
switch (clock_idx) {
case CPUCLOCK_PROF:
if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
tsk->signal->cputime_expires.prof_exp = *newval;
break;
case CPUCLOCK_VIRT:
if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
tsk->signal->cputime_expires.virt_exp = *newval;
break;
}
tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 94 | 55.62% | 2 | 18.18% |
| Stanislaw Gruszka | 28 | 16.57% | 1 | 9.09% |
| Frédéric Weisbecker | 23 | 13.61% | 5 | 45.45% |
| Frank Mayhar | 19 | 11.24% | 1 | 9.09% |
| Martin Schwidefsky | 4 | 2.37% | 1 | 9.09% |
| Peter Zijlstra | 1 | 0.59% | 1 | 9.09% |
| Total | 169 | 100.00% | 11 | 100.00% |
static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
const struct timespec64 *rqtp)
{
struct itimerspec64 it;
struct k_itimer timer;
u64 expires;
int error;
/*
* Set up a temporary timer and then wait for it to go off.
*/
memset(&timer, 0, sizeof timer);
spin_lock_init(&timer.it_lock);
timer.it_clock = which_clock;
timer.it_overrun = -1;
error = posix_cpu_timer_create(&timer);
timer.it_process = current;
if (!error) {
static struct itimerspec64 zero_it;
struct restart_block *restart;
memset(&it, 0, sizeof(it));
it.it_value = *rqtp;
spin_lock_irq(&timer.it_lock);
error = posix_cpu_timer_set(&timer, flags, &it, NULL);
if (error) {
spin_unlock_irq(&timer.it_lock);
return error;
}
while (!signal_pending(current)) {
if (timer.it.cpu.expires == 0) {
/*
* Our timer fired and was reset, below
* deletion can not fail.
*/
posix_cpu_timer_del(&timer);
spin_unlock_irq(&timer.it_lock);
return 0;
}
/*
* Block until cpu_timer_fire (or a signal) wakes us.
*/
__set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_irq(&timer.it_lock);
schedule();
spin_lock_irq(&timer.it_lock);
}
/*
* We were interrupted by a signal.
*/
expires = timer.it.cpu.expires;
error = posix_cpu_timer_set(&timer, 0, &zero_it, &it);
if (!error) {
/*
* Timer is now unarmed, deletion can not fail.
*/
posix_cpu_timer_del(&timer);
}
spin_unlock_irq(&timer.it_lock);
while (error == TIMER_RETRY) {
/*
* We need to handle case when timer was or is in the
* middle of firing. In other cases we already freed
* resources.
*/
spin_lock_irq(&timer.it_lock);
error = posix_cpu_timer_del(&timer);
spin_unlock_irq(&timer.it_lock);
}
if ((it.it_value.tv_sec | it.it_value.tv_nsec) == 0) {
/*
* It actually did fire already.
*/
return 0;
}
error = -ERESTART_RESTARTBLOCK;
/*
* Report back to the user the time still remaining.
*/
restart = ¤t->restart_block;
restart->nanosleep.expires = expires;
if (restart->nanosleep.type != TT_NONE)
error = nanosleep_copyout(restart, &it.it_value);
}
return error;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 232 | 61.70% | 2 | 15.38% |
| Stanislaw Gruszka | 56 | 14.89% | 1 | 7.69% |
| Al Viro | 48 | 12.77% | 3 | 23.08% |
| Toyo Abe | 23 | 6.12% | 1 | 7.69% |
| Thomas Gleixner | 10 | 2.66% | 2 | 15.38% |
| Deepa Dinamani | 6 | 1.60% | 3 | 23.08% |
| Frédéric Weisbecker | 1 | 0.27% | 1 | 7.69% |
| Total | 376 | 100.00% | 13 | 100.00% |
static long posix_cpu_nsleep_restart(struct restart_block *restart_block);
static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
const struct timespec64 *rqtp)
{
struct restart_block *restart_block = ¤t->restart_block;
int error;
/*
* Diagnose required errors first.
*/
if (CPUCLOCK_PERTHREAD(which_clock) &&
(CPUCLOCK_PID(which_clock) == 0 ||
CPUCLOCK_PID(which_clock) == task_pid_vnr(current)))
return -EINVAL;
error = do_cpu_nanosleep(which_clock, flags, rqtp);
if (error == -ERESTART_RESTARTBLOCK) {
if (flags & TIMER_ABSTIME)
return -ERESTARTNOHAND;
restart_block->fn = posix_cpu_nsleep_restart;
restart_block->nanosleep.clockid = which_clock;
}
return error;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Toyo Abe | 78 | 70.91% | 2 | 18.18% |
| Roland McGrath | 22 | 20.00% | 2 | 18.18% |
| Thomas Gleixner | 5 | 4.55% | 4 | 36.36% |
| Eric W. Biedermann | 3 | 2.73% | 1 | 9.09% |
| Deepa Dinamani | 1 | 0.91% | 1 | 9.09% |
| Andrew Lutomirski | 1 | 0.91% | 1 | 9.09% |
| Total | 110 | 100.00% | 11 | 100.00% |
static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
{
clockid_t which_clock = restart_block->nanosleep.clockid;
struct timespec64 t;
t = ns_to_timespec64(restart_block->nanosleep.expires);
return do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 28 | 60.87% | 2 | 20.00% |
| Thomas Gleixner | 13 | 28.26% | 4 | 40.00% |
| Deepa Dinamani | 2 | 4.35% | 1 | 10.00% |
| Toyo Abe | 2 | 4.35% | 2 | 20.00% |
| Al Viro | 1 | 2.17% | 1 | 10.00% |
| Total | 46 | 100.00% | 10 | 100.00% |
#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED)
static int process_cpu_clock_getres(const clockid_t which_clock,
struct timespec64 *tp)
{
return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 21 | 91.30% | 1 | 33.33% |
| Deepa Dinamani | 1 | 4.35% | 1 | 33.33% |
| Thomas Gleixner | 1 | 4.35% | 1 | 33.33% |
| Total | 23 | 100.00% | 3 | 100.00% |
static int process_cpu_clock_get(const clockid_t which_clock,
struct timespec64 *tp)
{
return posix_cpu_clock_get(PROCESS_CLOCK, tp);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 21 | 91.30% | 1 | 33.33% |
| Deepa Dinamani | 1 | 4.35% | 1 | 33.33% |
| Thomas Gleixner | 1 | 4.35% | 1 | 33.33% |
| Total | 23 | 100.00% | 3 | 100.00% |
static int process_cpu_timer_create(struct k_itimer *timer)
{
timer->it_clock = PROCESS_CLOCK;
return posix_cpu_timer_create(timer);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 23 | 100.00% | 1 | 100.00% |
| Total | 23 | 100.00% | 1 | 100.00% |
static int process_cpu_nsleep(const clockid_t which_clock, int flags,
const struct timespec64 *rqtp)
{
return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 26 | 89.66% | 1 | 25.00% |
| Thomas Gleixner | 2 | 6.90% | 2 | 50.00% |
| Deepa Dinamani | 1 | 3.45% | 1 | 25.00% |
| Total | 29 | 100.00% | 4 | 100.00% |
static int thread_cpu_clock_getres(const clockid_t which_clock,
struct timespec64 *tp)
{
return posix_cpu_clock_getres(THREAD_CLOCK, tp);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 21 | 91.30% | 1 | 33.33% |
| Thomas Gleixner | 1 | 4.35% | 1 | 33.33% |
| Deepa Dinamani | 1 | 4.35% | 1 | 33.33% |
| Total | 23 | 100.00% | 3 | 100.00% |
static int thread_cpu_clock_get(const clockid_t which_clock,
struct timespec64 *tp)
{
return posix_cpu_clock_get(THREAD_CLOCK, tp);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 21 | 91.30% | 1 | 33.33% |
| Deepa Dinamani | 1 | 4.35% | 1 | 33.33% |
| Thomas Gleixner | 1 | 4.35% | 1 | 33.33% |
| Total | 23 | 100.00% | 3 | 100.00% |
static int thread_cpu_timer_create(struct k_itimer *timer)
{
timer->it_clock = THREAD_CLOCK;
return posix_cpu_timer_create(timer);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 23 | 100.00% | 1 | 100.00% |
| Total | 23 | 100.00% | 1 | 100.00% |
const struct k_clock clock_posix_cpu = {
.clock_getres = posix_cpu_clock_getres,
.clock_set = posix_cpu_clock_set,
.clock_get = posix_cpu_clock_get,
.timer_create = posix_cpu_timer_create,
.nsleep = posix_cpu_nsleep,
.timer_set = posix_cpu_timer_set,
.timer_del = posix_cpu_timer_del,
.timer_get = posix_cpu_timer_get,
.timer_rearm = posix_cpu_timer_rearm,
};
const struct k_clock clock_process = {
.clock_getres = process_cpu_clock_getres,
.clock_get = process_cpu_clock_get,
.timer_create = process_cpu_timer_create,
.nsleep = process_cpu_nsleep,
};
const struct k_clock clock_thread = {
.clock_getres = thread_cpu_clock_getres,
.clock_get = thread_cpu_clock_get,
.timer_create = thread_cpu_timer_create,
};
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Roland McGrath | 2111 | 39.95% | 6 | 5.08% |
| Frank Mayhar | 1003 | 18.98% | 2 | 1.69% |
| Frédéric Weisbecker | 586 | 11.09% | 18 | 15.25% |
| Stanislaw Gruszka | 340 | 6.43% | 13 | 11.02% |
| Peter Zijlstra | 301 | 5.70% | 8 | 6.78% |
| Jason Low | 220 | 4.16% | 6 | 5.08% |
| Thomas Gleixner | 172 | 3.26% | 17 | 14.41% |
| Toyo Abe | 103 | 1.95% | 2 | 1.69% |
| Oleg Nesterov | 75 | 1.42% | 7 | 5.93% |
| Jiri Slaby | 61 | 1.15% | 3 | 2.54% |
| Martin Schwidefsky | 57 | 1.08% | 2 | 1.69% |
| Al Viro | 52 | 0.98% | 3 | 2.54% |
| Arun Raghavan | 44 | 0.83% | 1 | 0.85% |
| Deepa Dinamani | 27 | 0.51% | 6 | 5.08% |
| Xiao Guangrong | 22 | 0.42% | 1 | 0.85% |
| Linus Torvalds | 16 | 0.30% | 4 | 3.39% |
| Hidetoshi Seto | 15 | 0.28% | 1 | 0.85% |
| Krzysztof Opasiak | 15 | 0.28% | 1 | 0.85% |
| Ingo Molnar | 13 | 0.25% | 3 | 2.54% |
| Hiroshi Shimamoto | 12 | 0.23% | 1 | 0.85% |
| Sergey Senozhatsky | 10 | 0.19% | 1 | 0.85% |
| Christoph Hellwig | 7 | 0.13% | 1 | 0.85% |
| Roman Zippel | 4 | 0.08% | 1 | 0.85% |
| Pavel Emelyanov | 3 | 0.06% | 2 | 1.69% |
| Eric W. Biedermann | 3 | 0.06% | 1 | 0.85% |
| Petr Tesarik | 3 | 0.06% | 1 | 0.85% |
| H Hartley Sweeten | 3 | 0.06% | 1 | 0.85% |
| Nick Kossifidis | 2 | 0.04% | 1 | 0.85% |
| Greg Kroah-Hartman | 1 | 0.02% | 1 | 0.85% |
| Lucas De Marchi | 1 | 0.02% | 1 | 0.85% |
| Alexey Dobriyan | 1 | 0.02% | 1 | 0.85% |
| Andrew Lutomirski | 1 | 0.02% | 1 | 0.85% |
| Total | 5284 | 100.00% | 118 | 100.00% |
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