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| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2016-06-16 15:57:01 +0300 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2017-06-13 09:29:21 -0400 |
| commit | 709dcf11a35318f4d9b8aeb0c5c144fd59fbabc1 (patch) | |
| tree | 1d581bc967003052bf63cb13590c28c99bf06604 /kernel/sysctl_binary.c | |
| parent | 0f665ed5581f1c4e6cf1353484a0f625b2bf88a0 (diff) | |
sched/fair: Initialize throttle_count for new task-groups lazily
[ Upstream commit 094f469172e00d6ab0a3130b0e01c83b3cf3a98d ]
Cgroup created inside throttled group must inherit current throttle_count.
Broken throttle_count allows to nominate throttled entries as a next buddy,
later this leads to null pointer dereference in pick_next_task_fair().
This patch initialize cfs_rq->throttle_count at first enqueue: laziness
allows to skip locking all rq at group creation. Lazy approach also allows
to skip full sub-tree scan at throttling hierarchy (not in this patch).
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bsegall@google.com
Link: http://lkml.kernel.org/r/146608182119.21870.8439834428248129633.stgit@buzz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'kernel/sysctl_binary.c')
0 files changed, 0 insertions, 0 deletions