From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>,
linux-kernel@vger.kernel.org,
linux-s390 <linux-s390@vger.kernel.org>,
linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Noam Camus <noamc@ezchip.com>,
Christian Borntraeger <borntraeger@de.ibm.com>
Subject: [PATCH 2/5] stop_machine: yield CPU during stop machine
Date: Fri, 21 Oct 2016 13:58:55 +0200 [thread overview]
Message-ID: <1477051138-1610-3-git-send-email-borntraeger@de.ibm.com> (raw)
In-Reply-To: <1477051138-1610-1-git-send-email-borntraeger@de.ibm.com>
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.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
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
next prev parent reply other threads:[~2016-10-21 11:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-21 11:58 [PATCH/RFC 0/5] cpu_relax: introduce yield, remove lowlatency Christian Borntraeger
2016-10-21 11:58 ` [PATCH 1/5] processor.h: introduce cpu_relax_yield Christian Borntraeger
2016-10-21 11:58 ` Christian Borntraeger [this message]
2016-10-21 12:05 ` [PATCH 2/5] stop_machine: yield CPU during stop machine Peter Zijlstra
2016-10-21 12:41 ` Juergen Gross
2016-10-22 0:06 ` Nicholas Piggin
2016-10-24 7:52 ` Christian Borntraeger
2016-10-24 8:47 ` Peter Zijlstra
2016-10-21 11:58 ` [PATCH 3/5] s390: make cpu_relax a barrier again Christian Borntraeger
2016-10-21 11:58 ` [PATCH 4/5] Remove cpu_relax_lowlatency users Christian Borntraeger
2016-10-21 11:58 ` [PATCH 5/5] remove cpu_relax_lowlatency Christian Borntraeger
2016-10-21 12:06 ` [PATCH/RFC 0/5] cpu_relax: introduce yield, remove lowlatency Peter Zijlstra
2016-10-21 14:57 ` David Miller
2016-10-21 15:08 ` Christian Borntraeger
2016-10-21 15:12 ` David Miller
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