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From: Christoph Lameter <cl@linux-foundation.org>
To: Roger Oksanen <roger.oksanen@cs.helsinki.fi>
Cc: linux-mm <linux-mm@kvack.org>, Mel Gorman <mel@csn.ul.ie>
Subject: Re: [RFC,PATCH 2/2] dmapool: Honor GFP_* flags.
Date: Wed, 2 Dec 2009 16:05:51 -0600 (CST)	[thread overview]
Message-ID: <alpine.DEB.2.00.0912021558490.6282@router.home> (raw)
In-Reply-To: <200912022339.55552.roger.oksanen@cs.helsinki.fi>

On Wed, 2 Dec 2009, Roger Oksanen wrote:

> That would fundamentally change how the pool allocator works. Currently it
> waits on its own wait queue for returned memory from dma_pool_free(..).

Plus it also has a timeout. What usually triggers first? Repeated attempts
and a timeout... All smells like heuristics that better be avoided.

> Waiting in the page allocator won't allow it to claim memory returned there.

If __GFP_WAIT is set then the page allocator can perform direct reclaim
getting you the memory you want!


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  reply	other threads:[~2009-12-02 22:06 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-02 13:18 [RFC,PATCH 0/2] dmapool: allocation gfp changes Roger Oksanen
2009-12-02 13:20 ` [RFC,PATCH 1/2] dmapool: Don't warn when allowed to retry allocation Roger Oksanen
2009-12-02 19:56   ` Christoph Lameter
2009-12-02 21:22     ` Roger Oksanen
2009-12-02 13:23 ` [RFC,PATCH 2/2] dmapool: Honor GFP_* flags Roger Oksanen
2009-12-02 20:00   ` Christoph Lameter
2009-12-02 21:39     ` Roger Oksanen
2009-12-02 22:05       ` Christoph Lameter [this message]
2009-12-03 12:10     ` Mel Gorman

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