rcu: improve RCU CPU stall-warning messages

[safe/jmp/linux-2.6] / kernel / posix-cpu-timers.c

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 18bdde6..bc7704b 100644 (file)
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -8,6 +8,7 @@
 #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.
@@ -383,7 +384,8 @@ int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
 
 /*
  * Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
- * This is called from sys_timer_create with the new timer already locked.
+ * This is called from sys_timer_create() and do_cpu_nanosleep() with the
+ * new timer already all-zeros initialized.
  */
 int posix_cpu_timer_create(struct k_itimer *new_timer)
 {
@@ -395,8 +397,6 @@ int posix_cpu_timer_create(struct k_itimer *new_timer)
                return -EINVAL;
 
        INIT_LIST_HEAD(&new_timer->it.cpu.entry);
-       new_timer->it.cpu.incr.sched = 0;
-       new_timer->it.cpu.expires.sched = 0;
 
        read_lock(&tasklist_lock);
        if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
@@ -521,11 +521,12 @@ void posix_cpu_timers_exit(struct task_struct *tsk)
 }
 void posix_cpu_timers_exit_group(struct task_struct *tsk)
 {
-       struct task_cputime cputime;
+       struct signal_struct *const sig = tsk->signal;
 
-       thread_group_cputimer(tsk, &cputime);
        cleanup_timers(tsk->signal->cpu_timers,
-                      cputime.utime, cputime.stime, cputime.sum_exec_runtime);
+                      cputime_add(tsk->utime, sig->utime),
+                      cputime_add(tsk->stime, sig->stime),
+                      tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
 }
 
 static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
@@ -981,6 +982,7 @@ static void check_thread_timers(struct task_struct *tsk,
        int maxfire;
        struct list_head *timers = tsk->cpu_timers;
        struct signal_struct *const sig = tsk->signal;
+       unsigned long soft;
 
        maxfire = 20;
        tsk->cputime_expires.prof_exp = cputime_zero;
@@ -1029,9 +1031,10 @@ static void check_thread_timers(struct task_struct *tsk,
        /*
         * Check for the special case thread timers.
         */
-       if (sig->rlim[RLIMIT_RTTIME].rlim_cur != RLIM_INFINITY) {
-               unsigned long hard = sig->rlim[RLIMIT_RTTIME].rlim_max;
-               unsigned long *soft = &sig->rlim[RLIMIT_RTTIME].rlim_cur;
+       soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
+       if (soft != RLIM_INFINITY) {
+               unsigned long hard =
+                       ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
 
                if (hard != RLIM_INFINITY &&
                    tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
@@ -1042,14 +1045,13 @@ static void check_thread_timers(struct task_struct *tsk,
                        __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
                        return;
                }
-               if (tsk->rt.timeout > DIV_ROUND_UP(*soft, USEC_PER_SEC/HZ)) {
+               if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
                        /*
                         * At the soft limit, send a SIGXCPU every second.
                         */
-                       if (sig->rlim[RLIMIT_RTTIME].rlim_cur
-                           < sig->rlim[RLIMIT_RTTIME].rlim_max) {
-                               sig->rlim[RLIMIT_RTTIME].rlim_cur +=
-                                                               USEC_PER_SEC;
+                       if (soft < hard) {
+                               soft += USEC_PER_SEC;
+                               sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
                        }
                        printk(KERN_INFO
                                "RT Watchdog Timeout: %s[%d]\n",
@@ -1059,9 +1061,9 @@ static void check_thread_timers(struct task_struct *tsk,
        }
 }
 
-static void stop_process_timers(struct task_struct *tsk)
+static void stop_process_timers(struct signal_struct *sig)
 {
-       struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
+       struct thread_group_cputimer *cputimer = &sig->cputimer;
        unsigned long flags;
 
        if (!cputimer->running)
@@ -1070,6 +1072,10 @@ static void stop_process_timers(struct task_struct *tsk)
        spin_lock_irqsave(&cputimer->lock, flags);
        cputimer->running = 0;
        spin_unlock_irqrestore(&cputimer->lock, flags);
+
+       sig->cputime_expires.prof_exp = cputime_zero;
+       sig->cputime_expires.virt_exp = cputime_zero;
+       sig->cputime_expires.sched_exp = 0;
 }
 
 static u32 onecputick;
@@ -1089,9 +1095,13 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
                                                          cputime_one_jiffy);
                                it->error -= onecputick;
                        }
-               } else
+               } 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);
        }
 
@@ -1116,6 +1126,7 @@ static void check_process_timers(struct task_struct *tsk,
        unsigned long long sum_sched_runtime, sched_expires;
        struct list_head *timers = sig->cpu_timers;
        struct task_cputime cputime;
+       unsigned long soft;
 
        /*
         * Don't sample the current process CPU clocks if there are no timers.
@@ -1126,7 +1137,7 @@ static void check_process_timers(struct task_struct *tsk,
            list_empty(&timers[CPUCLOCK_VIRT]) &&
            cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
            list_empty(&timers[CPUCLOCK_SCHED])) {
-               stop_process_timers(tsk);
+               stop_process_timers(sig);
                return;
        }
 
@@ -1188,11 +1199,13 @@ static void check_process_timers(struct task_struct *tsk,
                         SIGPROF);
        check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
                         SIGVTALRM);
-
-       if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
+       soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
+       if (soft != RLIM_INFINITY) {
                unsigned long psecs = cputime_to_secs(ptime);
+               unsigned long hard =
+                       ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
                cputime_t x;
-               if (psecs >= sig->rlim[RLIMIT_CPU].rlim_max) {
+               if (psecs >= hard) {
                        /*
                         * At the hard limit, we just die.
                         * No need to calculate anything else now.
@@ -1200,17 +1213,17 @@ static void check_process_timers(struct task_struct *tsk,
                        __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
                        return;
                }
-               if (psecs >= sig->rlim[RLIMIT_CPU].rlim_cur) {
+               if (psecs >= soft) {
                        /*
                         * At the soft limit, send a SIGXCPU every second.
                         */
                        __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
-                       if (sig->rlim[RLIMIT_CPU].rlim_cur
-                           < sig->rlim[RLIMIT_CPU].rlim_max) {
-                               sig->rlim[RLIMIT_CPU].rlim_cur++;
+                       if (soft < hard) {
+                               soft++;
+                               sig->rlim[RLIMIT_CPU].rlim_cur = soft;
                        }
                }
-               x = secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
+               x = secs_to_cputime(soft);
                if (cputime_eq(prof_expires, cputime_zero) ||
                    cputime_lt(x, prof_expires)) {
                        prof_expires = x;