Re: [PATCH 2/5] stop_machine: yield CPU during stop machine
From: Peter Zijlstra <peterz@infradead.org>
Date: 2016-10-21 12:05:49
Also in:
kvm, linux-arch, linux-s390, lkml, virtualization
On Fri, Oct 21, 2016 at 01:58:55PM +0200, Christian Borntraeger wrote:
stop_machine can take a very long time if the hypervisor does overcommitment for guest CPUs. When waiting for "the one", lets give up our CPU by using the new cpu_relax_yield.
This seems something that would apply to most other virt stuff. Lets Cc a few more lists for that.
quoted hunk ↗ jump to hunk
Signed-off-by: Christian Borntraeger <redacted> --- kernel/stop_machine.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index ec9ab2f..1eb8266 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c@@ -194,7 +194,7 @@ static int multi_cpu_stop(void *data) /* Simple state machine */ do { /* Chill out and ensure we re-read multi_stop_state. */ - cpu_relax(); + cpu_relax_yield(); if (msdata->state != curstate) { curstate = msdata->state; switch (curstate) {-- 2.5.5