From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752853Ab1IPNUH (ORCPT ); Fri, 16 Sep 2011 09:20:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46599 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751907Ab1IPNUF (ORCPT ); Fri, 16 Sep 2011 09:20:05 -0400 Date: Fri, 16 Sep 2011 09:19:30 -0400 From: Josef Bacik To: Matthew Wilcox Cc: Andi Kleen , viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Improve lseek scalability v3 Message-ID: <20110916131929.GA27738@dhcp231-156.rdu.redhat.com> References: <1316128013-21980-1-git-send-email-andi@firstfloor.org> <20110916130054.GA8997@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110916130054.GA8997@parisc-linux.org> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 16, 2011 at 07:00:55AM -0600, Matthew Wilcox wrote: > On Thu, Sep 15, 2011 at 04:06:46PM -0700, Andi Kleen wrote: > > Currently generic_file_llseek users synchronize all on the inode i_mutex, > > which is very heavy handed because it affects even different processes. > > > > This patchkit attempts to make generic_file_llseek (mostly) lockless. > > Yes, but, are there any real workloads which care? I know will-it-scale > says that lseek doesn't scale, but any real app which has a seek-heavy > workload is surely using pread()/pwrite() by now ... after all, they > were in UNIX98 so they've been a standard for 13 years. > Apparently postgresql uses lseek heavily http://rhaas.blogspot.com/2011/08/linux-and-glibc-scalability.html Thanks, Josef