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From: James Bottomley <James.Bottomley@steeleye.com>
To: "Adam J. Richter" <adam@yggdrasil.com>
Cc: akpm@digeo.com, James.Bottomley@SteelEye.com,
	david-b@pacbell.net, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] generic device DMA (dma_pool update)
Date: Wed, 01 Jan 2003 13:48:11 -0600	[thread overview]
Message-ID: <200301011948.h01JmBo02789@localhost.localdomain> (raw)
In-Reply-To: Message from "Adam J. Richter" <adam@yggdrasil.com>  of "Wed, 01 Jan 2003 11:21:58 PST." <200301011921.LAA02354@baldur.yggdrasil.com>

adam@yggdrasil.com said:
> 	I thought Andrew Morton's request for a gfp flag was for allocating
> memory from a pool (for example, a "read ahead" will want to abort if
> memory is unavailable rather than wait).

Well, yes, but the underlying allocators will also have to take the flag too 
so that all the semantics are correct.


adam@yggdrasil.com said:
> 	Can someone show me or invent an example of two different uses of
> dma_alloc_coherent that really should use different policies on
> whether to block or not? 

The obvious one is allocations from interrupt routines, which must be 
GFP_ATOMIC (ignoring the issue of whether a driver should be doing a memory 
allocation in an interrupt).  Allocating large pools at driver initialisation 
should probably be GFP_KERNEL as you say.

James




  reply	other threads:[~2003-01-01 19:39 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-01-01 19:21 [PATCH] generic device DMA (dma_pool update) Adam J. Richter
2003-01-01 19:48 ` James Bottomley [this message]
2003-01-02  2:11   ` David Brownell
  -- strict thread matches above, loose matches on Subject: below --
2003-01-02 22:07 Adam J. Richter
2003-01-03  0:20 ` Russell King
2003-01-03  4:50 ` David Brownell
2003-01-03  6:11 ` David Brownell
2003-01-03  6:46 ` David Brownell
2003-01-03  6:52   ` William Lee Irwin III
2003-01-02 17:04 Adam J. Richter
2003-01-02  4:13 Adam J. Richter
2003-01-02 16:41 ` James Bottomley
2003-01-02 18:26 ` David Brownell
2003-01-01  0:02 Adam J. Richter
2002-12-31 23:38 Adam J. Richter
2002-12-31 22:02 Adam J. Richter
2002-12-31 22:41 ` Andrew Morton
2002-12-31 23:23   ` David Brownell
2002-12-31 23:27     ` Andrew Morton
2002-12-31 23:44       ` David Brownell
2002-12-31 23:47     ` James Bottomley
2003-01-01 17:10   ` James Bottomley
2002-12-31 23:35 ` David Brownell
2002-12-27 21:40 [RFT][PATCH] generic device DMA implementation James Bottomley
2002-12-28  1:56 ` David Brownell
2002-12-30 23:11   ` [PATCH] generic device DMA (dma_pool update) David Brownell
2002-12-31 15:00     ` James Bottomley
2002-12-31 17:04       ` David Brownell
2002-12-31 17:23         ` James Bottomley
2002-12-31 18:11           ` David Brownell
2002-12-31 18:44             ` James Bottomley
2002-12-31 19:29               ` David Brownell
2002-12-31 19:50                 ` James Bottomley
2002-12-31 21:17                   ` David Brownell
2002-12-31 16:36     ` James Bottomley
2002-12-31 17:32       ` David Brownell

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