From: "Ricardo M. Correia" <ricardo.correia@oracle.com>
To: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org, andreas.dilger@oracle.com,
behlendorf1@llnl.gov
Subject: Re: [PATCH] Fix unconditional GFP_KERNEL allocations in __vmalloc().
Date: Wed, 15 Dec 2010 03:53:20 +0100 [thread overview]
Message-ID: <1292381600.2994.6.camel@oralap> (raw)
In-Reply-To: <1292381126-5710-1-git-send-email-ricardo.correia@oracle.com>
On Wed, 2010-12-15 at 03:45 +0100, Ricardo M. Correia wrote:
> (Patch based on 2.6.36 tag).
>
> These GFP_KERNEL allocations could happen even though the caller of __vmalloc()
> requested a stricter gfp mask (such as GFP_NOFS or GFP_ATOMIC).
Sorry for taking a while to write this patch. For the discussion behind
it, you can read: http://marc.info/?t=128942209500002&r=1&w=2
Please note that I have only tested this patch on my laptop (x86-64)
with one Kconfig.
Since I have done all these changes manually and I don't have any
non-x86-64 machines, it's possible that I may have typoed or missed
something and that this patch may break compilation on other
architectures or with other config options.
Any suggestions are welcome.
Thanks,
Ricardo
> This was first noticed in Lustre, where it led to deadlocks due to a filesystem
> thread which requested a GFP_NOFS __vmalloc() allocation ended up calling down
> to Lustre itself to free memory, despite this not being allowed by GFP_NOFS.
>
> Further analysis showed that some in-tree filesystems (namely GFS, Ceph and XFS)
> were vulnerable to the same bug due to calling __vmalloc() or vm_map_ram() in
> contexts where __GFP_FS allocations are not allowed.
>
> Fixing this bug required changing a few mm interfaces to accept gfp flags.
> This needed to be done in all architectures, thus the large number of changes.
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next prev parent reply other threads:[~2010-12-15 2:59 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-15 2:45 [PATCH] Fix unconditional GFP_KERNEL allocations in __vmalloc() Ricardo M. Correia
2010-12-15 2:53 ` Ricardo M. Correia [this message]
2010-12-15 3:48 ` Cross compilers (Was: Re: [PATCH] Fix unconditional GFP_KERNEL allocations in __vmalloc().) Stephen Rothwell
2010-12-23 21:37 ` Randy Dunlap
2011-01-09 23:17 ` Tony Breeds
2010-12-17 7:27 ` [PATCH] Fix unconditional GFP_KERNEL allocations in __vmalloc() KOSAKI Motohiro
2010-12-23 21:08 ` David Rientjes
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