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Subject: Re: suppress page allocation failure warnings from sys_listxattr
From: Colin Walters <walters@verbum.org>
To: Dave Jones <davej@redhat.com>
Cc: viro@zeniv.linux.org.uk, Linux Kernel <linux-kernel@vger.kernel.org>
Date: Tue, 13 Mar 2012 17:33:55 -0400
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References: <20120313182220.GA11500@redhat.com>
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On Tue, 2012-03-13 at 14:22 -0400, Dave Jones wrote:
> This size is user controllable, and so it's trivial for someone to trigger a
> stream of order:4 page allocation errors.

I spent some time today struggling with an order:4 allocation failure
(my application uses CLONE_NEWNET to make an empty network stack for
software builds, and apparently one of the netfilter caches requires
this).

But is that the general principle, that we just add GFP_NOWARN if the
allocation size is trivially user controllable?  I guess examples like
fs/pipe.c:pipe_set_size() agree with you, but it feels kind of like
it's papering over the problem...