From: Christoph Lameter <cl@linux.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
hannes@cmpxchg.org, penguin-kernel@I-love.SAKURA.ne.jp
Subject: Re: vmstat: make vmstat_updater deferrable again and shut down on idle
Date: Mon, 14 Dec 2015 12:32:23 -0600 (CST) [thread overview]
Message-ID: <alpine.DEB.2.20.1512141230560.25288@east.gentwo.org> (raw)
In-Reply-To: <alpine.DEB.2.20.1512101940230.21007@east.gentwo.org>
Hmmm... We got a race condition since quiet_vmstat touches cpu_stat_off
which may not be allocated early in the bootup sequence. Causes oopses on
boot.
Subject: vmstat: quieting vmstat requires a running system
Do not do anything unless the system is actually running. Otherwise
we may crash on bootup.
Signed-off-by: Christoph Lameter <cl@linux.com>
Index: linux/mm/vmstat.c
===================================================================
--- linux.orig/mm/vmstat.c
+++ linux/mm/vmstat.c
@@ -1270,6 +1270,9 @@ static void vmstat_update(struct work_st
*/
void quiet_vmstat(void)
{
+ if (system_state != SYSTEM_RUNNING)
+ return;
+
do {
if (!cpumask_test_and_set_cpu(smp_processor_id(), cpu_stat_off))
cancel_delayed_work(this_cpu_ptr(&vmstat_work));
--
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next prev parent reply other threads:[~2015-12-14 18:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-10 20:45 Christoph Lameter
2015-12-10 23:31 ` Andrew Morton
2015-12-11 1:41 ` Christoph Lameter
2015-12-14 18:32 ` Christoph Lameter [this message]
2016-01-20 13:52 ` Shiraz Hashim
2016-01-20 15:12 ` Christoph Lameter
2016-01-21 6:24 ` Shiraz Hashim
2016-01-21 15:41 ` Christoph Lameter
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