Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752337AbcDBGe7 (ORCPT ); Sat, 2 Apr 2016 02:34:59 -0400 Received: from mail-vk0-f53.google.com ([209.85.213.53]:34930 "EHLO mail-vk0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751336AbcDBGe5 (ORCPT ); Sat, 2 Apr 2016 02:34:57 -0400 MIME-Version: 1.0 Reply-To: sedat.dilek@gmail.com In-Reply-To: <20160330184732.GO7822@mtj.duckdns.org> References: <56E7C009.3070008@gmail.com> <56F70255.6070806@gmail.com> <20160330184732.GO7822@mtj.duckdns.org> Date: Sat, 2 Apr 2016 08:34:56 +0200 Message-ID: Subject: Re: [fuse-devel] Horrible mmap write performance (kernel writeback issue?) From: Sedat Dilek To: Tejun Heo Cc: Miklos Szeredi , Jakob Unterwurzacher , fuse-devel , Linux-Fsdevel , Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1015 Lines: 35 On Wed, Mar 30, 2016 at 8:47 PM, Tejun Heo wrote: > Hello, > > On Mon, Mar 28, 2016 at 09:45:53PM +0200, Miklos Szeredi wrote: >> >> commit 947e9762a8ddefda38aa21e249e6a4fec215cd12 >> >> Author: Tejun Heo >> >> Date: Fri May 22 18:23:32 2015 -0400 >> >> >> >> writeback: update wb_over_bg_thresh() to use wb_domain aware operations >> > >> >> Tejun, >> >> Any idea why this commit stalls fuse mmap writes? >> >> Here's the start of the this thread: >> >> http://marc.info/?l=fuse-devel&m=145008058603261&w=2 > > Hmmm... cgroup writeback support shouldn't affect fuse at all as the > backing device doesn't enable cgroup support. I probably made some > silly mistake. Is there a simple reproducer I can play with? > > Thanks. > To quote Jakob from a previous email: "I you want to reproduce, clone https://github.com/rfjakob/mmapwrite.git and run ./encfs-test.sh (needs encfs installed). On the bad kernel, it will hang within a few seconds." Hope this helps. - Sedat -