From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f70.google.com (mail-pa0-f70.google.com [209.85.220.70]) by kanga.kvack.org (Postfix) with ESMTP id ED6EC6B0038 for ; Sun, 16 Oct 2016 17:19:12 -0400 (EDT) Received: by mail-pa0-f70.google.com with SMTP id hm5so179594582pac.4 for ; Sun, 16 Oct 2016 14:19:12 -0700 (PDT) Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net. [150.101.137.143]) by mx.google.com with ESMTP id u83si27736684pfk.205.2016.10.16.14.19.10 for ; Sun, 16 Oct 2016 14:19:11 -0700 (PDT) Date: Mon, 17 Oct 2016 07:49:59 +1100 From: Dave Chinner Subject: Re: [RFC PATCH] mm, compaction: allow compaction for GFP_NOFS requests Message-ID: <20161016204959.GH27872@dastard> References: <20161004081215.5563-1-mhocko@kernel.org> <20161004203202.GY9806@dastard> <20161005113839.GC7138@dhcp22.suse.cz> <20161006021142.GC9806@dastard> <20161007131814.GL18439@dhcp22.suse.cz> <20161013002924.GO23194@dastard> <20161013073947.GF21678@dhcp22.suse.cz> <20161013110456.GK21678@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161013110456.GK21678@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Mel Gorman , Vlastimil Babka , Joonsoo Kim , Andrew Morton , linux-mm@kvack.org, LKML On Thu, Oct 13, 2016 at 01:04:56PM +0200, Michal Hocko wrote: > On Thu 13-10-16 09:39:47, Michal Hocko wrote: > > On Thu 13-10-16 11:29:24, Dave Chinner wrote: > > > On Fri, Oct 07, 2016 at 03:18:14PM +0200, Michal Hocko wrote: > > [...] > > > > Unpatched kernel: > > > > # Version 3.3, 16 thread(s) starting at Fri Oct 7 09:55:05 2016 > > > > # Sync method: NO SYNC: Test does not issue sync() or fsync() calls. > > > > # Directories: Time based hash between directories across 10000 subdirectories with 180 seconds per subdirectory. > > > > # File names: 40 bytes long, (16 initial bytes of time stamp with 24 random bytes at end of name) > > > > # Files info: size 0 bytes, written with an IO size of 16384 bytes per write > > > > # App overhead is time in microseconds spent in the test not doing file writing related system calls. > > > > # > > > > FSUse% Count Size Files/sec App Overhead > > > > 1 1600000 0 4300.1 20745838 > > > > 3 3200000 0 4239.9 23849857 > > > > 5 4800000 0 4243.4 25939543 > > > > 6 6400000 0 4248.4 19514050 > > > > 8 8000000 0 4262.1 20796169 > > > > 9 9600000 0 4257.6 21288675 > > > > 11 11200000 0 4259.7 19375120 > > > > 13 12800000 0 4220.7 22734141 > > > > 14 14400000 0 4238.5 31936458 > > > > 16 16000000 0 4231.5 23409901 > > > > 18 17600000 0 4045.3 23577700 > > > > 19 19200000 0 2783.4 58299526 > > > > 21 20800000 0 2678.2 40616302 > > > > 23 22400000 0 2693.5 83973996 > > > > Ctrl+C because it just took too long. > > > > > > Try running it on a larger filesystem, or configure the fs with more > > > AGs and a larger log (i.e. mkfs.xfs -f -dagcount=24 -l size=512m > > > ). That will speed up modifications and increase concurrency. > > > This test should be able to run 5-10x faster than this (it > > > sustains 55,000 files/s @ 300MB/s write on my test fs on a cheap > > > SSD). > > > > Will add more memory to the machine. Will report back on that. > > increasing the memory to 1G didn't help. So I've tried to add > -dagcount=24 -l size=512m and that didn't help much either. I am at 5k > files/s so nowhere close to your 55k. I thought this is more about CPUs > count than about the amount of memory. So I've tried a larger machine > with 24 CPUs (no dagcount etc...), this one doesn't have a fast storage > so I've backed the fs image by ramdisk but even then I am getting very > similar results. No idea what is wrong with my kvm setup. What's the backing storage? I use an image file in an XFS filesystem, configured with virtio,cache=none so it's concurrency model matches that of a real disk... Cheers, Dave. -- Dave Chinner david@fromorbit.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org