On 06/06/2014 03:05 PM, Sasha Levin wrote:
On 05/30/2014 10:07 AM, Jan Kara wrote:
On Fri 30-05-14 09:58:14, Peter Hurley wrote:
On 05/30/2014 09:11 AM, Sasha Levin wrote:
Hi all,
I sometime see lockups when booting my KVM guest with the latest -next kernel,
it basically hangs right when it should start 'init', and after a while I get
the following spew:
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
Maybe related to this report: https://lkml.org/lkml/2014/5/30/26
from Jet Chen which was bisected to
commit bafe980f5afc7ccc693fd8c81c8aa5a02fbb5ae0
Author: Jan Kara <j...@suse.cz>
AuthorDate: Thu May 22 10:43:35 2014 +1000
Commit: Stephen Rothwell <s...@canb.auug.org.au>
CommitDate: Thu May 22 10:43:35 2014 +1000
printk: enable interrupts before calling console_trylock_for_printk()
We need interrupts disabled when calling console_trylock_for_printk()
only
so that cpu id we pass to can_use_console() remains valid (for other
things console_sem provides all the exclusion we need and deadlocks on
console_sem due to interrupts are impossible because we use
down_trylock()). However if we are rescheduled, we are guaranteed to run
on an online cpu so we can easily just get the cpu id in
can_use_console().
We can lose a bit of performance when we enable interrupts in
vprintk_emit() and then disable them again in console_unlock() but OTOH it
can somewhat reduce interrupt latency caused by console_unlock()
especially since later in the patch series we will want to spin on
console_sem in console_trylock_for_printk().
Signed-off-by: Jan Kara <j...@suse.cz>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
?
Yeah, very likely. I think I see the problem, I'll send the fix shortly.
Hi Jan,
It seems that the issue I'm seeing is different from the "[prink] BUG: spinlock
lockup suspected on CPU#0, swapper/1".
Is there anything else I could try here? The issue is very common during
testing.
Sasha,
Is this bisectable? Maybe that's the best way forward here.
Regards,
Peter Hurley
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