Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753800AbYKSJpZ (ORCPT ); Wed, 19 Nov 2008 04:45:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752679AbYKSJpN (ORCPT ); Wed, 19 Nov 2008 04:45:13 -0500 Received: from mail-qy0-f11.google.com ([209.85.221.11]:65350 "EHLO mail-qy0-f11.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752508AbYKSJpL (ORCPT ); Wed, 19 Nov 2008 04:45:11 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=XkSJ/Vp7VT+vmgZECXkebybkiXp3su9MaMVXgWwYDDkqxhvZ30eTleoMBvzFoXbzNO 3xj1H6JEgg1Y9cCWCMUytqS0OuHuYYZl34i8nUOl6dvdsGGBhP4ECnIVGmSGrTV6b4Ui redl82jJAV5lqfR8xz05WOgh/4JDvKDh7gx7U= Message-ID: Date: Wed, 19 Nov 2008 10:45:09 +0100 From: "Leon Woestenberg" To: "FUJITA Tomonori" Subject: Re: pci_map_sg() does not coalesce adjacent physical memory? x86 Cc: jens.axboe@oracle.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, James.Bottomley@hansenpartnership.com, tj@kernel.org In-Reply-To: <20081119165915A.fujita.tomonori@lab.ntt.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081119142016E.fujita.tomonori@lab.ntt.co.jp> <20081119155847U.fujita.tomonori@lab.ntt.co.jp> <20081119165915A.fujita.tomonori@lab.ntt.co.jp> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1086 Lines: 32 Hello, On Wed, Nov 19, 2008 at 8:58 AM, FUJITA Tomonori wrote: > On Wed, 19 Nov 2008 15:58:12 +0900 > FUJITA Tomonori wrote: >> On Wed, 19 Nov 2008 07:22:31 +0100 > > - pci_map_sg/dma_map_sg are used with a scatter gather list that > doesn't come from the block layer (e.g. some network drivers do). > This is the point I then want to make: we have pci_map_sg() users in other system than the block layer, the network and v4l2 subsystems, why cannot they benefit from coalescing? Should they copy the block layer coalescing implementation, or should that implementation be made more generic and live outside the block sub system? My intended use case is as follows. See the sg_write() call for the code flow. http://www.sidebranch.com/leon/user_dma_sg.c Thanks, -- Leon -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/