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From: Andy Whitcroft <apw@shadowen.org>
To: Christoph Lameter <clameter@engr.sgi.com>
Cc: Andrew Morton <akpm@osdl.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Mel Gorman <mel@csn.ul.ie>
Subject: Re: [PATCH 2/5] lumpy: isolate_lru_pages wants to specifically take active or inactive pages
Date: Fri, 02 Mar 2007 15:57:14 +0000	[thread overview]
Message-ID: <45E8495A.4080501@shadowen.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0702281015340.21257@schroedinger.engr.sgi.com>

Christoph Lameter wrote:
> On Tue, 27 Feb 2007, Andy Whitcroft wrote:
> 
>> The caller of isolate_lru_pages specifically knows whether it wants
>> to take either inactive or active pages.  Currently we take the
>> state of the LRU page at hand and use that to scan for matching
>> pages in the order sized block.  If that page is transiting we
>> can scan for the wrong type.  The caller knows what they want and
>> should be telling us.  Pass in the required active/inactive state
>> and match against that.
> 
> The page cannot be transiting since we hold the lru lock?

As you say it should be gated by lru_lock and we should not expect to
see pages with the wrong type on the list.  I would swear that I was
seeing pages on the wrong list there for a bit in testing and mistakenly
thought they were in transition.  A quick review at least says thats
false.  So I'll reinstate the BUG() and retest to see if I am smoking
crack or there is a bigger bug out there.

-apw

  reply	other threads:[~2007-03-02 15:58 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-27 19:33 [PATCH 0/5] Lumpy Reclaim V4 Andy Whitcroft
2007-02-27 19:34 ` [PATCH 1/5] Lumpy Reclaim V3 Andy Whitcroft
2007-02-28 18:14   ` Christoph Lameter
2007-03-02 15:45     ` Andy Whitcroft
2007-02-27 19:34 ` [PATCH 2/5] lumpy: isolate_lru_pages wants to specifically take active or inactive pages Andy Whitcroft
2007-02-28 18:17   ` Christoph Lameter
2007-03-02 15:57     ` Andy Whitcroft [this message]
2007-02-27 19:35 ` [PATCH 3/5] lumpy: ensure that we compare PageActive and active safely Andy Whitcroft
2007-02-27 19:35 ` [PATCH 4/5] lumpy: update commentry on subtle comparisons and rounding assumptions Andy Whitcroft
2007-02-27 19:36 ` [PATCH 5/5] lumpy: only check for valid pages when holes are present Andy Whitcroft

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