diff options
Diffstat (limited to 'kernel/sched/cputime.c')
| -rw-r--r-- | kernel/sched/cputime.c | 20 |
1 files changed, 5 insertions, 15 deletions
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 7097de2c8cda..4f97896887ec 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -313,10 +313,8 @@ static u64 read_sum_exec_runtime(struct task_struct *t) void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) { struct signal_struct *sig = tsk->signal; - u64 utime, stime; struct task_struct *t; - unsigned int seq, nextseq; - unsigned long flags; + u64 utime, stime; /* * Update current task runtime to account pending time since last @@ -329,27 +327,19 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) if (same_thread_group(current, tsk)) (void) task_sched_runtime(current); - rcu_read_lock(); - /* Attempt a lockless read on the first round. */ - nextseq = 0; - do { - seq = nextseq; - flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); + guard(rcu)(); + scoped_seqlock_read (&sig->stats_lock, ss_lock_irqsave) { times->utime = sig->utime; times->stime = sig->stime; times->sum_exec_runtime = sig->sum_sched_runtime; - for_each_thread(tsk, t) { + __for_each_thread(sig, t) { task_cputime(t, &utime, &stime); times->utime += utime; times->stime += stime; times->sum_exec_runtime += read_sum_exec_runtime(t); } - /* If lockless access failed, take the lock. */ - nextseq = 1; - } while (need_seqretry(&sig->stats_lock, seq)); - done_seqretry_irqrestore(&sig->stats_lock, seq, flags); - rcu_read_unlock(); + } } #ifdef CONFIG_IRQ_TIME_ACCOUNTING |