From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.fusionio.com ([66.114.96.31]:55947 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752223Ab2HXSmL (ORCPT ); Fri, 24 Aug 2012 14:42:11 -0400 Received: from mail1.int.fusionio.com (mail1.int.fusionio.com [10.101.1.21]) by mx2.fusionio.com with ESMTP id VWFRZSHbT6ZhwW1x (version=TLSv1 cipher=AES128-SHA bits=128 verify=NO) for ; Fri, 24 Aug 2012 12:42:10 -0600 (MDT) Date: Fri, 24 Aug 2012 14:42:08 -0400 From: Chris Mason To: Josef Bacik CC: "linux-btrfs@vger.kernel.org" Subject: Re: [PATCH] Btrfs: turbo charge fsync Message-ID: <20120824184208.GA22819@shiny> References: <1345833808-1539-1-git-send-email-jbacik@fusionio.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <1345833808-1539-1-git-send-email-jbacik@fusionio.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, Aug 24, 2012 at 12:43:28PM -0600, Josef Bacik wrote: > > Original Patched > SATA drive 82KB/s 140KB/s > Fusion drive 431KB/s 2532KB/s > > So around 2-6 times faster depending on your hardware. There are a few > corner cases, for example if you truncate at all we have to do it the old > way since there is no way to be sure what is in the log is ok. This > probably could be done smarter, but if you write-fsync-truncate-write-fsync > you deserve what you get. All this work is in RAM of course so if your > inode gets evicted from cache and you read it in and fsync it we'll do it > the slow way if we are still in the same transaction that we last modified > the inode in. I think I sent Liubo down the wrong path on this one, and Josef and I banged out some ideas for a different (hopefully less complex) way to solve the problem. Josef, these results look fantastic. -chris