From: Christoph Lameter <clameter@sgi.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hugh@veritas.com>, linux-mm@kvack.org
Subject: Re: Drop PageReclaim()
Date: Thu, 8 Feb 2007 17:06:33 -0800 (PST) [thread overview]
Message-ID: <Pine.LNX.4.64.0702081700360.15866@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20070208163953.ab2bd694.akpm@linux-foundation.org>
On Thu, 8 Feb 2007, Andrew Morton wrote:
> I doubt it. One would need to troll five-year-old changelogs and mailing
> list discussion, but iirc that rotation was a large win in certain
> workloads, preventing scanning meltdowns and general memory stress.
I'd expect trouble here because of the taking of a LRU lock per page. For
large amounts of concurrent I/O this could be an issue.
> > One additional issue that is raised by the writeback pages remaining on
> > the LRU lists is that we can get into the same livelock situation as with
> > mlocked pages if we keep on skipping over writeback pages.
>
> That's why we rotate the reclaimable pages back to the head-of-queue.
I think the reclaim writeout is one minor contributor here. If there are
large amounts of writeback pages from f.e. streaming general I/O then we
may run still into bad situations because we need to scan over them.
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next prev parent reply other threads:[~2007-02-09 1:06 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-07 14:13 Drop PageReclaim() Christoph Lameter
2007-02-07 14:32 ` Hugh Dickins
2007-02-08 21:20 ` Christoph Lameter
2007-02-08 21:38 ` Christoph Lameter
2007-02-08 21:42 ` Christoph Lameter
2007-02-08 21:55 ` Christoph Lameter
2007-02-08 22:03 ` Andrew Morton
2007-02-08 22:14 ` Christoph Lameter
2007-02-08 22:24 ` Andrew Morton
2007-02-08 22:26 ` Christoph Lameter
2007-02-08 22:37 ` Andrew Morton
2007-02-08 22:40 ` Christoph Lameter
2007-02-08 23:13 ` Andrew Morton
2007-02-09 0:22 ` Christoph Lameter
2007-02-09 0:39 ` Andrew Morton
2007-02-09 1:06 ` Christoph Lameter [this message]
2007-02-09 1:18 ` Andrew Morton
2007-02-11 5:12 ` Rik van Riel
2007-02-07 17:25 ` Andrew Morton
2007-02-08 21:19 ` Christoph Lameter
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