Commit-ID: 49bd21efe7fc84f9c82c8475b8ff6f8b865b1692
Gitweb: http://git.kernel.org/tip/49bd21efe7fc84f9c82c8475b8ff6f8b865b1692
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Tue, 20 Sep 2016 22:06:01 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 30 Sep 2016 11:03:28 +0200
sched/core: Fix set_user_nice()
Almost all scheduler functions update state with the following
pattern:
if (queued)
dequeue_task(rq, p, DEQUEUE_SAVE);
if (running)
put_prev_task(rq, p);
/* update state */
if (queued)
enqueue_task(rq, p, ENQUEUE_RESTORE);
if (running)
set_curr_task(rq, p);
set_user_nice() however misses the running part, cure this.
This was found by asserting we never enqueue 'current'.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/core.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ce69fc7..aae08ce 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3724,7 +3724,8 @@ out_unlock:
void set_user_nice(struct task_struct *p, long nice)
{
- int old_prio, delta, queued;
+ bool queued, running;
+ int old_prio, delta;
struct rq_flags rf;
struct rq *rq;
@@ -3746,8 +3747,11 @@ void set_user_nice(struct task_struct *p, long nice)
goto out_unlock;
}
queued = task_on_rq_queued(p);
+ running = task_current(rq, p);
if (queued)
dequeue_task(rq, p, DEQUEUE_SAVE);
+ if (running)
+ put_prev_task(rq, p);
p->static_prio = NICE_TO_PRIO(nice);
set_load_weight(p);
@@ -3764,6 +3768,8 @@ void set_user_nice(struct task_struct *p, long nice)
if (delta < 0 || (delta > 0 && task_running(rq, p)))
resched_curr(rq);
}
+ if (running)
+ set_curr_task(rq, p);
out_unlock:
task_rq_unlock(rq, p, &rf);
}
--
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