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Date: Tue, 10 Jan 2012 17:50:28 +0100
Message-ID: <CAJfpegvTPH9_KpJxYDbOU7YzsB=Uq=d706iGJK21BRy_UoWF=w@mail.gmail.com>
Subject: Re: [RFC PATCH] shrink_dcache_parent() deadlock
From: Miklos Szeredi <miklos@szeredi.hu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>, Dave Chinner <david@fromorbit.com>,
        Christoph Hellwig <hch@infradead.org>, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, mgorman@suse.de, gregkh@suse.de,
        akpm@linux-foundation.org
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On Tue, Jan 10, 2012 at 5:33 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> Hmm. Even if they are never run in parallel, I think it would be much
> nicer to do it in both, just so that there would be a conceptual
> consistency of "when we remove the dentry from the LRU list and put it
> on our pruning list, we set the bit". That cacheline will be dirty
> anyway (due to the list move and getting the dentry lock), so setting
> a bit is not expensive - but having odd inconsistent ad-hoc rules is
> nasty.

Makes sense.

I'm testing the modified patch right now and will post shortly.

Thanks,
Miklos