Fix a context switch performance regression.
Signed-off-by: Ingo Molnar <firstname.lastname@example.org>
sched: Optimize finish_lock_switch()
The kernel test robot measured a -1.6% performance regression on
will-it-scale/sched_yield due to commit:
2558aacff858 ("sched/hotplug: Ensure only per-cpu kthreads run during hotplug")
Even though we were careful to replace a single load with another
single load from the same cacheline.
Restore finish_lock_switch() to the exact state before the offending
patch and solve the problem differently.
Fixes: 2558aacff858 ("sched/hotplug: Ensure only per-cpu kthreads run during hotplug")
Reported-by: kernel test robot <email@example.com>
Signed-off-by: Peter Zijlstra (Intel) <firstname.lastname@example.org>
2 files changed