From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f194.google.com ([209.85.220.194]:36184 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751940AbdCPSBo (ORCPT ); Thu, 16 Mar 2017 14:01:44 -0400 Received: by mail-qk0-f194.google.com with SMTP id n141so6964177qke.3 for ; Thu, 16 Mar 2017 11:01:43 -0700 (PDT) Message-ID: <1489686825.2650.3.camel@poochiereds.net> Subject: Re: [Lsf-pc] [LSF/MM TOPIC] Performance of seekdir(SEEK_HOLE/DATA) and FIEMAP From: Jeff Layton To: Trond Myklebust , "lsf-pc@lists.linux-foundation.org" Cc: "linux-fsdevel@vger.kernel.org" Date: Thu, 16 Mar 2017 13:53:45 -0400 In-Reply-To: <1489680539.3151.3.camel@primarydata.com> References: <1489680539.3151.3.camel@primarydata.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, 2017-03-16 at 16:09 +0000, Trond Myklebust wrote: > Hi all, > > If there are any free slots on the filesystem track, then it would be > nice to have a conversation about use of FIEMAP and SEEK_HOLE/DATA > performance. > > The issue is this: as large sparse files become more prevalent, there > is a potential performance advantage to be made if applications can > quickly and easily detect areas of no data. > Full disclosure: my interest here is seeing Anna's work on implementing > the NFSv4.2 sparse file support come to fruition; right now she is > finding that the performance of the filesystem tools (both seekdir() > and FIEMAP) are insufficient to allow us to implement the READPLUS (htt > ps://tools.ietf.org/html/rfc7862#section-6.2.1) operation and realise > the promised performance goals. > > If there is time left on the schedule, then it might be nice to have a > full discussion of this topic with all the filesystem folks present, > but if not, we could do it as a lightning talk. > > Thanks > Trond > It turns out that we still had one open slot later in the afternoon on Tuesday so I added this there. Cheers, -- Jeff Layton