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 <[email protected]> >> > AuthorDate: Thu May 22 10:43:35 2014 +1000 >> > Commit: Stephen Rothwell <[email protected]> >> > 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 <[email protected]> >> > Signed-off-by: Andrew Morton <[email protected]> >> > >> > ? > 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. Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
