From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754668Ab1IPNA6 (ORCPT ); Fri, 16 Sep 2011 09:00:58 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:60692 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754300Ab1IPNA4 (ORCPT ); Fri, 16 Sep 2011 09:00:56 -0400 Date: Fri, 16 Sep 2011 07:00:55 -0600 From: Matthew Wilcox To: Andi Kleen Cc: viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Improve lseek scalability v3 Message-ID: <20110916130054.GA8997@parisc-linux.org> References: <1316128013-21980-1-git-send-email-andi@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1316128013-21980-1-git-send-email-andi@firstfloor.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."