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Subject: Re: [patch 03/33] fs: scale files_lock
From: Peter Zijlstra <peterz@infradead.org>
To: npiggin@suse.de
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
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Date: Mon, 28 Sep 2009 15:24:08 +0200
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On Fri, 2009-09-04 at 16:51 +1000, npiggin@suse.de wrote:
> Improve scalability of files_lock by adding per-cpu, per-sb files lists,
> protected with per-cpu locking. Effectively turning it into a big-writer
> lock.

What I did was fine-grain locking the double linked list so that you can
delete items without hitting a global lock.

For addition I added per-cpu list-heads that would be spliced onto the
global list once in a while.

Granted, the code was a tad involved... and hch wanted to get rid of
these lists, which is of course a much better solution.