From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mondschein.lichtvoll.de ([194.150.191.11]:44906 "EHLO mail.lichtvoll.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752247Ab2HBLZS convert rfc822-to-8bit (ORCPT ); Thu, 2 Aug 2012 07:25:18 -0400 From: Martin Steigerwald To: linux-btrfs@vger.kernel.org Subject: Re: How can btrfs take 23sec to stat 23K files from an SSD? Date: Thu, 2 Aug 2012 13:25:17 +0200 Cc: Marc MERLIN , "Fajar A. Nugraha" References: <20120722185848.GA10089@merlins.org> <201208012357.39786.Martin@lichtvoll.de> <20120802050741.GA22772@merlins.org> (sfid-20120802_121045_885836_CB856E78) In-Reply-To: <20120802050741.GA22772@merlins.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Message-Id: <201208021325.17433.Martin@lichtvoll.de> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Am Donnerstag, 2. August 2012 schrieb Marc MERLIN: > So, doctor, is it bad? :) > > randomwrite: (g=0): rw=randwrite, bs=2K-16K/2K-16K, ioengine=libaio, iodepth=64 > sequentialwrite: (g=1): rw=write, bs=2K-16K/2K-16K, ioengine=libaio, iodepth=64 > randomread: (g=2): rw=randread, bs=2K-16K/2K-16K, ioengine=libaio, iodepth=64 > sequentialread: (g=3): rw=read, bs=2K-16K/2K-16K, ioengine=libaio, iodepth=64 > 2.0.8 > Starting 4 processes > randomwrite: Laying out IO file(s) (1 file(s) / 2048MB) > Jobs: 1 (f=1): [___R] [100.0% done] [558.8M/0K /s] [63.8K/0 iops] [eta 00m:00s] > randomwrite: (groupid=0, jobs=1): err= 0: pid=7193 > write: io=102048KB, bw=1700.8KB/s, iops=189 , runt= 60003msec > slat (usec): min=21 , max=219834 , avg=5250.91, stdev=5936.55 > clat (usec): min=25 , max=738932 , avg=329339.45, stdev=106004.63 > lat (msec): min=4 , max=751 , avg=334.59, stdev=107.57 > clat percentiles (msec): Heck, I didnīt look at the IOPS figure! 189 IOPS for a SATA-600 SSD. Thats pathetic. So again, please test this without dm_crypt. I canīt believe that this is the maximum the hardware is able to achieve. A really fast 15000 rpm SAS harddisk might top that. -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7