From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomas Carnecky Subject: fixing slow sync(2) Date: Sat, 08 Oct 2011 17:24:15 +0200 Message-ID: <4E906B1F.6010609@dbservice.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed To: linux-btrfs@vger.kernel.org Return-path: List-ID: The issue with sync(2) being slow has been known for a while now (I can find discussions as early as July 2010). But nobody seems to be willing to fix it or even figure out out what the actual problem is. I use btrfs on two hosts, and the sync(2) syscall is consistently slow. By slow I mean 20 seconds on one and 45(!) seconds on the other. Every single time, no exceptions. Is there anything I can do to help track down the cause? I can test patches, trace the kernel or use whatever tool is most helpful. tom