Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759979AbZCaNdZ (ORCPT ); Tue, 31 Mar 2009 09:33:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756545AbZCaNdL (ORCPT ); Tue, 31 Mar 2009 09:33:11 -0400 Received: from rcsinet11.oracle.com ([148.87.113.123]:45884 "EHLO rgminet11.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754940AbZCaNdK (ORCPT ); Tue, 31 Mar 2009 09:33:10 -0400 Subject: Re: [PATCH 1/7] block: Add block_flush_device() From: Chris Mason To: Mark Lord Cc: Jens Axboe , Linus Torvalds , Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao , Jeff Garzik , Christoph Hellwig , Theodore Tso , Ingo Molnar , Alan Cox , Arjan van de Ven , Andrew Morton , Peter Zijlstra , Nick Piggin , David Rees , Jesper Krogh , Linux Kernel Mailing List , david@fromorbit.com, tj@kernel.org In-Reply-To: <49D21939.4050106@rtr.ca> References: <49D02328.7060108@oss.ntt.co.jp> <49D0258A.9020306@garzik.org> <49D03377.1040909@oss.ntt.co.jp> <49D0B535.2010106@oss.ntt.co.jp> <49D0B687.1030407@oss.ntt.co.jp> <20090330175544.GX5178@kernel.dk> <20090330185414.GZ5178@kernel.dk> <20090330201732.GB5178@kernel.dk> <49D13123.7040007@rtr.ca> <1238505376.8363.26.camel@think.oraclecorp.com> <49D21939.4050106@rtr.ca> Content-Type: text/plain Date: Tue, 31 Mar 2009 09:28:18 -0400 Message-Id: <1238506098.8363.31.camel@think.oraclecorp.com> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 Content-Transfer-Encoding: 7bit X-Source-IP: acsmt706.oracle.com [141.146.40.84] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A09020A.49D21A7D.00CC:SCFMA4539814,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 693 Lines: 23 On Tue, 2009-03-31 at 09:23 -0400, Mark Lord wrote: > Chris Mason wrote: > > > > You can test this pretty easily: > > > > dd if=/dev/zero of=foo bs=4k count=10000 oflag=direct > > > > If that runs faster than 1MB/s the write cache is still on. > .. > > Or simply: hdparm -W /dev/sd? ## (for SATA/PATA drives) I'm afraid I tend to hammer on the drive instead of asking it politely, but I guess hdparm is trust worthy these days ;) -chris -- 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/