From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@osdl.org>
Date: Mon, 22 Nov 2004 22:45:07 +0000
Subject: Re: deferred rss update instead of sloppy rss
Message-Id: <20041122144507.484a7627.akpm@osdl.org>
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To: Christoph Lameter <clameter@sgi.com>
Cc: hugh@veritas.com, torvalds@osdl.org, benh@kernel.crashing.org, nickpiggin@yahoo.com.au, linux-mm@kvack.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org

Christoph Lameter <clameter@sgi.com> wrote:
>
> > just to prevent transient gross inaccuracies.  For some value of "16".
> 
> The page fault code only increments rss. For larger transactions that
> increase / decrease rss significantly the page_table_lock is taken and
> mm->rss is updated directly. So no
> gross inaccuracies can result.

Sure.  Take a million successive pagefaults and mm->rss is grossly
inaccurate.  Hence my suggestion that it be spilled into mm->rss
periodically.