Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763859AbYGOWgB (ORCPT ); Tue, 15 Jul 2008 18:36:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763676AbYGOWcu (ORCPT ); Tue, 15 Jul 2008 18:32:50 -0400 Received: from mx1.redhat.com ([66.187.233.31]:37891 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763671AbYGOWct (ORCPT ); Tue, 15 Jul 2008 18:32:49 -0400 Date: Tue, 15 Jul 2008 18:32:37 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@devserv.devel.redhat.com To: David Miller cc: andi@firstfloor.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, jens.axboe@oracle.com Subject: Re: [SUGGESTION]: drop virtual merge accounting in I/O requests In-Reply-To: <20080714.183116.121978835.davem@davemloft.net> Message-ID: References: <20080714.143751.266098047.davem@davemloft.net> <20080714.183116.121978835.davem@davemloft.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1651 Lines: 41 On Mon, 14 Jul 2008, David Miller wrote: > From: Mikulas Patocka > Date: Mon, 14 Jul 2008 19:16:17 -0400 (EDT) > > > So the question is: to reduce number of requests by 12% on an outdated > > SCSI card, it is sensible to maintain complicated merge accounting logic > > in the core block layer? To me, it doesn't seem sensible. > > Rip out the code if you like, then. I really don't have time to > work on this myself. So if you do, by all means do whatever > you think is appropriate. So add signed-off line and forward it to Linus. Signed-off-by: Mikulas Patocka --- include/asm-sparc64/io.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) Index: linux-2.6.26-fast/include/asm-sparc64/io.h =================================================================== --- linux-2.6.26-fast.orig/include/asm-sparc64/io.h 2008-07-15 23:29:39.000000000 +0200 +++ linux-2.6.26-fast/include/asm-sparc64/io.h 2008-07-15 23:33:41.000000000 +0200 @@ -16,7 +16,10 @@ /* BIO layer definitions. */ extern unsigned long kern_base, kern_size; #define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT) -#define BIO_VMERGE_BOUNDARY 8192 + +/* Don't declare that we are virtual-merge capable because Sparc64 IOMMU code + doesn't guarantee that the merge is always possible */ +#define BIO_VMERGE_BOUNDARY 0 static inline u8 _inb(unsigned long addr) { -- 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/