timers: fix itimer/many thread hang, v2
This is the second resubmission of the posix timer rework patch, posted
a few days ago.
This includes the changes from the previous resubmittion, which addressed
Oleg Nesterov's comments, removing the RCU stuff from the patch and
un-inlining the thread_group_cputime() function for SMP.
In addition, per Ingo Molnar it simplifies the UP code, consolidating much
of it with the SMP version and depending on lower-level SMP/UP handling to
take care of the differences.
It also cleans up some UP compile errors, moves the scheduler stats-related
macros into kernel/sched_stats.h, cleans up a merge error in
kernel/fork.c and has a few other minor fixes and cleanups as suggested
by Oleg and Ingo. Thanks for the review, guys.
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index c51b5d2..260c22c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4039,55 +4039,22 @@
/*
* Return any ns on the sched_clock that have not yet been banked in
* @p in case that task is currently running.
- *
- * Called with task_rq_lock() held on @rq.
*/
-static unsigned long long task_delta_exec(struct task_struct *p, struct rq *rq)
+unsigned long long task_delta_exec(struct task_struct *p)
{
+ struct rq *rq;
+ unsigned long flags;
+ u64 ns = 0;
+
+ rq = task_rq_lock(p, &flags);
if (task_current(rq, p)) {
u64 delta_exec;
update_rq_clock(rq);
delta_exec = rq->clock - p->se.exec_start;
if ((s64)delta_exec > 0)
- return delta_exec;
+ ns = delta_exec;
}
- return 0;
-}
-
-/*
- * Return p->sum_exec_runtime plus any more ns on the sched_clock
- * that have not yet been banked in case the task is currently running.
- */
-unsigned long long task_sched_runtime(struct task_struct *p)
-{
- unsigned long flags;
- u64 ns;
- struct rq *rq;
-
- rq = task_rq_lock(p, &flags);
- ns = p->se.sum_exec_runtime + task_delta_exec(p, rq);
- task_rq_unlock(rq, &flags);
-
- return ns;
-}
-
-/*
- * Return sum_exec_runtime for the thread group plus any more ns on the
- * sched_clock that have not yet been banked in case the task is currently
- * running.
- */
-unsigned long long thread_group_sched_runtime(struct task_struct *p)
-{
- unsigned long flags;
- u64 ns;
- struct rq *rq;
- struct task_cputime totals;
-
- rq = task_rq_lock(p, &flags);
- thread_group_cputime(p, &totals);
- ns = totals.sum_exec_runtime + task_delta_exec(p, rq);
- task_rq_unlock(rq, &flags);
return ns;
}