From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Amerigo Wang <xiyou.wangcong@gmail.com>
Cc: Joao Correia <joaomiguelcorreia@gmail.com>,
linux-kernel@vger.kernel.org, Joerg Roedel <joerg.roedel@amd.com>
Subject: Re: lockdep max numbers (was Re: Crashes during boot on 2.6.30 / 2.6.31-rc, random programs)
Date: Thu, 02 Jul 2009 12:32:00 +0200 [thread overview]
Message-ID: <1246530720.4752.12.camel@laptop> (raw)
In-Reply-To: <20090702093120.GD6372@cr0.nay.redhat.com>
On Thu, 2009-07-02 at 17:31 +0800, Amerigo Wang wrote:
> On Wed, Jul 01, 2009 at 09:30:23PM +0100, Joao Correia wrote:
> >Hello again
> >
> >Looks like this just opened the lid on some other limits. I just hit
> >another thing, which hadn't shown up before i made the changes, but
> >looks like its just another limit thats too low. This one is harder to
> >reproduce tho.
> >
> >Jun 30 21:35:03 hightech kernel: BUG: MAX_LOCKDEP_CHAINS too low!
> >Jun 30 21:35:03 hightech kernel: turning off the locking correctness validator.
> >Jun 30 21:35:03 hightech kernel: Pid: 9379, comm: qemu-kvm Not tainted
>
>
> Similar problem...
>
> Peter? Would like to increase these numbers?
> >2.6.30-wl #3
> >Jun 30 21:35:03 hightech kernel: [<c05d0c66>] debug_dma_map_sg+0xe1/0x147
We recently fixed the dma debug stuff to require less lockdep resources,
Joerg might know if that made it into .30.
> >>>So i dug a little on the source and changed
> >>>
> >>>include/linux/sched.h
> >>>
> >>># define MAX_LOCK_DEPTH 48UL
> >>>
> >>>to
> >>>
> >>># define MAX_LOCK_DEPTH 96UL
> >> Let's Cc: Peter to see if he would like to change this number...
> >>
> >> Peter?
I really don't think we want to raise this, I mean, holding more that 48
locks at the same time is somewhat pushing it, don't you think?
Where do you run into this limit?
next prev parent reply other threads:[~2009-07-02 10:32 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-27 15:07 Crashes during boot on 2.6.30 / 2.6.31-rc, random programs Joao Correia
2009-06-27 15:11 ` Joao Correia
2009-06-29 2:08 ` Américo Wang
2009-06-29 8:53 ` Joao Correia
2009-06-29 9:15 ` Amerigo Wang
2009-06-29 10:30 ` Joao Correia
2009-06-30 9:16 ` Amerigo Wang
2009-07-01 20:30 ` Joao Correia
2009-07-02 9:31 ` lockdep max numbers (was Re: Crashes during boot on 2.6.30 / 2.6.31-rc, random programs) Amerigo Wang
2009-07-02 10:32 ` Peter Zijlstra [this message]
2009-07-02 10:45 ` Joao Correia
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