diff options
| author | Martin Pieuchot <mpi@cvs.openbsd.org> | 2017-02-09 10:27:04 +0000 |
|---|---|---|
| committer | Martin Pieuchot <mpi@cvs.openbsd.org> | 2017-02-09 10:27:04 +0000 |
| commit | 1872bfbf83c617ebcbe674d69858d971e7040e12 (patch) | |
| tree | d4113eca0a5875b351b5d4eb2f6eff30be753a4b /sys/kern | |
| parent | 180f29a2c42ef9f1e4564a2321227656d9cf732d (diff) | |
Do no select a CPU to execute the current thread when being preempt()ed.
Calling sched_choosecpu() at this moment often result in moving the thread
to a different CPU. This does not help the scheduler and creates a domino
effect, resulting in kernel thread moving to other CPUs.
Tested by many without performance impact. Simon Mages measured a small
performance improvement and a smaller variance with an http proxy.
Discussed with kettenis@, ok martijn@, beck@, visa@
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/sched_bsd.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/sys/kern/sched_bsd.c b/sys/kern/sched_bsd.c index fa349bafaab..7e420bc25b7 100644 --- a/sys/kern/sched_bsd.c +++ b/sys/kern/sched_bsd.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sched_bsd.c,v 1.44 2017/01/25 06:15:50 mpi Exp $ */ +/* $OpenBSD: sched_bsd.c,v 1.45 2017/02/09 10:27:03 mpi Exp $ */ /* $NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $ */ /*- @@ -329,7 +329,6 @@ preempt(struct proc *newp) SCHED_LOCK(s); p->p_priority = p->p_usrpri; p->p_stat = SRUN; - p->p_cpu = sched_choosecpu(p); setrunqueue(p); p->p_ru.ru_nivcsw++; mi_switch(); |