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Date: Thu, 3 May 2012 17:14:16 +1000
Message-ID: <CAPa8GCDzgbQ5T-4eR942KswxXwRE69rwV2CKgho6LOV-us5RDw@mail.gmail.com>
Subject: Re: [PATCH] vmalloc: add warning in __vmalloc
From: Nick Piggin <npiggin@gmail.com>
To: dedekind1@gmail.com
Cc: Sage Weil <sage@newdream.net>, Minchan Kim <minchan@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
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        rientjes@google.com, Neil Brown <neilb@suse.de>,
        David Woodhouse <dwmw2@infradead.org>, "Theodore Ts'o" <tytso@mit.edu>,
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        Steven Whitehouse <swhiteho@redhat.com>,
        "David S. Miller" <davem@davemloft.net>,
        James Morris <jmorris@namei.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>
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On 3 May 2012 17:13, Artem Bityutskiy <dedekind1@gmail.com> wrote:
> On Thu, 2012-05-03 at 16:30 +1000, Nick Piggin wrote:
>> Note that in writeback paths, a "good citizen" filesystem should not require
>> any allocations, or at least it should be able to tolerate allocation failures.
>> So fixing that would be a good idea anyway.
>
> This is a good point, but UBIFS kmallocs(GFP_NOFS) when doing I/O
> because it needs to compress/decompress. But I agree that if kmalloc
> fails, we should have a fall-back reserve buffer protected by a mutex
> for memory pressure situations.

AKA, a mempool :)