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Message-ID: <5c49b0ed0606081310q5771e8d1s55acef09b405922b@mail.gmail.com>
Date: Thu, 8 Jun 2006 13:10:11 -0700
From: "Nate Diller" <nate.diller@gmail.com>
To: "Peter Zijlstra" <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH] mm: tracking dirty pages -v6
Cc: "Hugh Dickins" <hugh@veritas.com>, linux-mm@kvack.org,
       linux-kernel@vger.kernel.org, "Andrew Morton" <akpm@osdl.org>,
       "David Howells" <dhowells@redhat.com>,
       "Christoph Lameter" <christoph@lameter.com>,
       "Martin Bligh" <mbligh@google.com>, "Nick Piggin" <npiggin@suse.de>,
       "Linus Torvalds" <torvalds@osdl.org>
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On 6/8/06, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
>
> From: Peter Zijlstra <a.p.zijlstra@chello.nl>
>
> People expressed the need to track dirty pages in shared mappings.
>
> Linus outlined the general idea of doing that through making clean
> writable pages write-protected and taking the write fault.
>
> This patch does exactly that, it makes pages in a shared writable
> mapping write-protected. On write-fault the pages are marked dirty and
> made writable. When the pages get synced with their backing store, the
> write-protection is re-instated.

Does this mean that processes dirtying pages via mmap are now subject
to write throttling?  That could dramatically change the performance
for tasks with a working set larger than 10% of memory.

NATE