Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752209AbcDZPHs (ORCPT ); Tue, 26 Apr 2016 11:07:48 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:38246 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751980AbcDZPHo (ORCPT ); Tue, 26 Apr 2016 11:07:44 -0400 Subject: Re: [PATCHSET v4 0/8] Make background writeback not suck To: References: <1460953487-3430-1-git-send-email-axboe@fb.com> CC: , , , , From: Jens Axboe Message-ID: <571F8434.9020804@fb.com> Date: Tue, 26 Apr 2016 09:07:32 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.54.13] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-04-26_08:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2853 Lines: 80 On 04/26/2016 01:04 AM, Sedat Dilek wrote: > Hi Jens, > > I am testing current linux-block.git#wb-buf-throttle on top of Linux > v4.6-rc5 here on my Ubuntu/precise AMD64. > ( Was installed as a WUBI "test" system - "testing" since April 2012 :-) .) Great! Thanks for testing. > Here are some numbers: > > # df -T | egrep 'sda|loop' > /dev/sda2 fuseblk 465546236 210981868 254564368 46% /host > /dev/loop0 ext4 17753424 15586612 1241936 93% / > > # egrep 'sda|loop|ext4' /etc/fstab > /host/ubuntu/disks/root.disk / ext4 > loop,errors=remount-ro 0 1 > /host/ubuntu/disks/swap.disk none swap loop,sw > 0 0 What kind of device is sda? > ( Not sure why I cannot do a find on /sys/block/ .) Probably the symlinks that confuse it. > # find /sys/devices/ -name '*wb_stat*' | egrep 'loop0|sda' > /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/queue/wb_stats > /sys/devices/virtual/block/loop0/queue/wb_stats > > # find /sys/devices/ -name '*wb_lat*' | egrep 'loop0|sda' > /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/queue/wb_lat_usec > /sys/devices/virtual/block/loop0/queue/wb_lat_usec > > # cat /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/queue/wb_stats > /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/queue/wb_lat_usec > background=8, normal=16, max=31, inflight=0, wait=0, bdp_wait=0 > 75000 > > # cat /sys/devices/virtual/block/loop0/queue/wb_stats > /sys/devices/virtual/block/loop0/queue/wb_lat_usec > background=16, normal=32, max=64, inflight=0, wait=0, bdp_wait=0 > 75000 > > Questions... > > Planning a v5? Yes, I'll post a v5 today or something like that. Functionally not a huge amount of changes, but it does have a few important bug fixes that make it perform better. The biggest part is making it generic, so it can be plugged into NFS as well, for instance. > Will this go to Linux v4.7 or later? > How should someone test? Probably a bit too tight for 4.7, but one can always hope. 4.8 is probably a more realistic target. Testing is really having some readers while you have writes going on. One example is doing something that reads while you have a dd writing to your device. Or interactive feel while installing a lot of packages, which tends to generate a ton of writes as well. If you are so inclined, I'd encourage you to test the v5 I'll post later today. I've run that through the paces on various devices. > Documentation... > > Can you add some more docs about getting infos (see above cat#s etc.) > below Documentation/ directory? > ( Talking about the stuff you have embedded in the commit-messages. ) Yeah, I'll do that, it is a bit light right now. It'll be in the next release. -- Jens Axboe