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Diffstat (limited to 'kernel/posix-cpu-timers.c')
-rw-r--r--kernel/posix-cpu-timers.c155
1 files changed, 85 insertions, 70 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index e33a21cb940..5c9dc228747 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -8,17 +8,18 @@
#include <linux/math64.h>
#include <asm/uaccess.h>
#include <linux/kernel_stat.h>
+#include <trace/events/timer.h>
/*
* Called after updating RLIMIT_CPU to set timer expiration if necessary.
*/
void update_rlimit_cpu(unsigned long rlim_new)
{
- cputime_t cputime;
+ cputime_t cputime = secs_to_cputime(rlim_new);
+ struct signal_struct *const sig = current->signal;
- cputime = secs_to_cputime(rlim_new);
- if (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
- cputime_gt(current->signal->it_prof_expires, cputime)) {
+ if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
+ cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
spin_lock_irq(&current->sighand->siglock);
set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
spin_unlock_irq(&current->sighand->siglock);
@@ -542,6 +543,17 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
now);
}
+static inline int expires_gt(cputime_t expires, cputime_t new_exp)
+{
+ return cputime_eq(expires, cputime_zero) ||
+ cputime_gt(expires, new_exp);
+}
+
+static inline int expires_le(cputime_t expires, cputime_t new_exp)
+{
+ return !cputime_eq(expires, cputime_zero) &&
+ cputime_le(expires, new_exp);
+}
/*
* Insert the timer on the appropriate list before any timers that
* expire later. This must be called with the tasklist_lock held
@@ -586,34 +598,32 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+ union cpu_time_count *exp = &nt->expires;
+
switch (CPUCLOCK_WHICH(timer->it_clock)) {
default:
BUG();
case CPUCLOCK_PROF:
- if (cputime_eq(p->cputime_expires.prof_exp,
- cputime_zero) ||
- cputime_gt(p->cputime_expires.prof_exp,
- nt->expires.cpu))
- p->cputime_expires.prof_exp =
- nt->expires.cpu;
+ if (expires_gt(p->cputime_expires.prof_exp,
+ exp->cpu))
+ p->cputime_expires.prof_exp = exp->cpu;
break;
case CPUCLOCK_VIRT:
- if (cputime_eq(p->cputime_expires.virt_exp,
- cputime_zero) ||
- cputime_gt(p->cputime_expires.virt_exp,
- nt->expires.cpu))
- p->cputime_expires.virt_exp =
- nt->expires.cpu;
+ if (expires_gt(p->cputime_expires.virt_exp,
+ exp->cpu))
+ p->cputime_expires.virt_exp = exp->cpu;
break;
case CPUCLOCK_SCHED:
if (p->cputime_expires.sched_exp == 0 ||
- p->cputime_expires.sched_exp >
- nt->expires.sched)
+ p->cputime_expires.sched_exp > exp->sched)
p->cputime_expires.sched_exp =
- nt->expires.sched;
+ exp->sched;
break;
}
} else {
+ struct signal_struct *const sig = p->signal;
+ union cpu_time_count *exp = &timer->it.cpu.expires;
+
/*
* For a process timer, set the cached expiration time.
*/
@@ -621,30 +631,23 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
default:
BUG();
case CPUCLOCK_VIRT:
- if (!cputime_eq(p->signal->it_virt_expires,
- cputime_zero) &&
- cputime_lt(p->signal->it_virt_expires,
- timer->it.cpu.expires.cpu))
+ if (expires_le(sig->it[CPUCLOCK_VIRT].expires,
+ exp->cpu))
break;
- p->signal->cputime_expires.virt_exp =
- timer->it.cpu.expires.cpu;
+ sig->cputime_expires.virt_exp = exp->cpu;
break;
case CPUCLOCK_PROF:
- if (!cputime_eq(p->signal->it_prof_expires,
- cputime_zero) &&
- cputime_lt(p->signal->it_prof_expires,
- timer->it.cpu.expires.cpu))
+ if (expires_le(sig->it[CPUCLOCK_PROF].expires,
+ exp->cpu))
break;
- i = p->signal->rlim[RLIMIT_CPU].rlim_cur;
+ i = sig->rlim[RLIMIT_CPU].rlim_cur;
if (i != RLIM_INFINITY &&
- i <= cputime_to_secs(timer->it.cpu.expires.cpu))
+ i <= cputime_to_secs(exp->cpu))
break;
- p->signal->cputime_expires.prof_exp =
- timer->it.cpu.expires.cpu;
+ sig->cputime_expires.prof_exp = exp->cpu;
break;
case CPUCLOCK_SCHED:
- p->signal->cputime_expires.sched_exp =
- timer->it.cpu.expires.sched;
+ sig->cputime_expires.sched_exp = exp->sched;
break;
}
}
@@ -1071,6 +1074,40 @@ static void stop_process_timers(struct task_struct *tsk)
spin_unlock_irqrestore(&cputimer->lock, flags);
}
+static u32 onecputick;
+
+static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
+ cputime_t *expires, cputime_t cur_time, int signo)
+{
+ if (cputime_eq(it->expires, cputime_zero))
+ return;
+
+ if (cputime_ge(cur_time, it->expires)) {
+ if (!cputime_eq(it->incr, cputime_zero)) {
+ it->expires = cputime_add(it->expires, it->incr);
+ it->error += it->incr_error;
+ if (it->error >= onecputick) {
+ it->expires = cputime_sub(it->expires,
+ cputime_one_jiffy);
+ it->error -= onecputick;
+ }
+ } else {
+ it->expires = cputime_zero;
+ }
+
+ 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 (!cputime_eq(it->expires, cputime_zero) &&
+ (cputime_eq(*expires, cputime_zero) ||
+ cputime_lt(it->expires, *expires))) {
+ *expires = it->expires;
+ }
+}
+
/*
* 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
@@ -1090,10 +1127,10 @@ static void check_process_timers(struct task_struct *tsk,
* Don't sample the current process CPU clocks if there are no timers.
*/
if (list_empty(&timers[CPUCLOCK_PROF]) &&
- cputime_eq(sig->it_prof_expires, cputime_zero) &&
+ cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) &&
sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
list_empty(&timers[CPUCLOCK_VIRT]) &&
- cputime_eq(sig->it_virt_expires, cputime_zero) &&
+ cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
list_empty(&timers[CPUCLOCK_SCHED])) {
stop_process_timers(tsk);
return;
@@ -1153,38 +1190,11 @@ static void check_process_timers(struct task_struct *tsk,
/*
* Check for the special case process timers.
*/
- if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
- if (cputime_ge(ptime, sig->it_prof_expires)) {
- /* ITIMER_PROF fires and reloads. */
- sig->it_prof_expires = sig->it_prof_incr;
- if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
- sig->it_prof_expires = cputime_add(
- sig->it_prof_expires, ptime);
- }
- __group_send_sig_info(SIGPROF, SEND_SIG_PRIV, tsk);
- }
- if (!cputime_eq(sig->it_prof_expires, cputime_zero) &&
- (cputime_eq(prof_expires, cputime_zero) ||
- cputime_lt(sig->it_prof_expires, prof_expires))) {
- prof_expires = sig->it_prof_expires;
- }
- }
- if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
- if (cputime_ge(utime, sig->it_virt_expires)) {
- /* ITIMER_VIRTUAL fires and reloads. */
- sig->it_virt_expires = sig->it_virt_incr;
- if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
- sig->it_virt_expires = cputime_add(
- sig->it_virt_expires, utime);
- }
- __group_send_sig_info(SIGVTALRM, SEND_SIG_PRIV, tsk);
- }
- if (!cputime_eq(sig->it_virt_expires, cputime_zero) &&
- (cputime_eq(virt_expires, cputime_zero) ||
- cputime_lt(sig->it_virt_expires, virt_expires))) {
- virt_expires = sig->it_virt_expires;
- }
- }
+ check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
+ SIGPROF);
+ check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
+ SIGVTALRM);
+
if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
unsigned long psecs = cputime_to_secs(ptime);
cputime_t x;
@@ -1457,7 +1467,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
if (!cputime_eq(*oldval, cputime_zero)) {
if (cputime_le(*oldval, now.cpu)) {
/* Just about to fire. */
- *oldval = jiffies_to_cputime(1);
+ *oldval = cputime_one_jiffy;
} else {
*oldval = cputime_sub(*oldval, now.cpu);
}
@@ -1703,10 +1713,15 @@ static __init int init_posix_cpu_timers(void)
.nsleep = thread_cpu_nsleep,
.nsleep_restart = thread_cpu_nsleep_restart,
};
+ struct timespec ts;
register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
+ cputime_to_timespec(cputime_one_jiffy, &ts);
+ onecputick = ts.tv_nsec;
+ WARN_ON(ts.tv_sec != 0);
+
return 0;
}
__initcall(init_posix_cpu_timers);