Messages in this thread | | | From | Paul Burton <> | Subject | [PATCH 0/2] sched: Fix a race between CPU onlining & user task scheduling | Date | Sat, 26 May 2018 08:46:46 -0700 |
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This short series fixes a race condition I've observed in which user tasks can be scheduled on CPUs that are still in the process of being brought online (or rather being made active) by hotplug.
I've created a small test case for the observed problem here:
https://gist.github.com/paulburton/25187c4f537263a6be9c8aac67bd33bf
The issue was first observed on a MIPS system running a test program that was sensitive to CPU affinity, but has been reproduced on x86_64 using the above program too. On my laptop with an Intel i7-5600U CPU the test tends to fail within 10 minutes, but with this series applied runs cleanly overnight.
Thanks, Paul
Paul Burton (2): sched: Make select_task_rq() require cpu_active() for user tasks sched: Warn if we fail to migrate a task
kernel/sched/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
-- 2.17.0
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