From owner-freebsd-scsi@FreeBSD.ORG Fri Jun 23 21:25:11 2006 Return-Path: X-Original-To: freebsd-scsi@freebsd.org Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2C7FF16A4A6 for ; Fri, 23 Jun 2006 21:25:11 +0000 (UTC) (envelope-from arcade@synergetica.dn.ua) Received: from nora.synergetica.dn.ua (synergetica.dn.ua [82.207.115.117]) by mx1.FreeBSD.org (Postfix) with ESMTP id D074C43D5A for ; Fri, 23 Jun 2006 21:25:09 +0000 (GMT) (envelope-from arcade@synergetica.dn.ua) Received: from [172.30.0.209] (yarn.lan [172.30.0.209]) (authenticated bits=0) by nora.synergetica.dn.ua (8.13.7/8.13.7) with ESMTP id k5NLP6IR065036; Sat, 24 Jun 2006 00:25:07 +0300 (EEST) (envelope-from arcade@synergetica.dn.ua) Message-ID: <449C5C32.1090808@synergetica.dn.ua> Date: Sat, 24 Jun 2006 00:25:06 +0300 From: Volodymyr Kostyrko User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; ru-RU; rv:1.8.0.4) Gecko/20060605 SeaMonkey/1.0.2 MIME-Version: 1.0 To: "Justin T. Gibbs" References: <4499B748.6040805@synergetica.dn.ua> <90D11403BD2140875BFEB24D@[10.0.0.22]> <449C0E34.3080005@synergetica.dn.ua> <5272604BA34A45926DFA0D2F@[10.0.0.22]> <449C1861.3080902@synergetica.dn.ua> <0C5F4B7D7A8779025C3E480D@[10.0.0.22]> In-Reply-To: <0C5F4B7D7A8779025C3E480D@[10.0.0.22]> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Cc: freebsd-scsi@freebsd.org Subject: Re: ahd(4) poor performance X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Jun 2006 21:25:11 -0000 Justin T. Gibbs wrote: > Access the raw device to bypass the filesystem and VM subsystem. > Start N dds where N is the queue depth you've configured for > the device. I've made almost the same test on /dev/da0s1b (the swap partition). Script: dd if=/dev/zero of=/dev/da0s1b count=20480& dd if=/dev/zero of=/dev/da0s1b count=20480& dd if=/dev/zero of=/dev/da0s1b count=20480& dd if=/dev/zero of=/dev/da0s1b count=20480& dd if=/dev/zero of=/dev/da0s1b count=20480& dd if=/dev/zero of=/dev/da0s1b count=20480& dd if=/dev/zero of=/dev/da0s1b count=20480& dd if=/dev/zero of=/dev/da0s1b count=20480& wait > camcontrol tags 0:0 -v (pass0:ahd0:0:0:0): dev_openings 8 (pass0:ahd0:0:0:0): dev_active 8 (pass0:ahd0:0:0:0): devq_openings 8 (pass0:ahd0:0:0:0): devq_queued 0 (pass0:ahd0:0:0:0): held 0 (pass0:ahd0:0:0:0): mintags 2 (pass0:ahd0:0:0:0): maxtags 255 2 users Load 0.31 0.49 0.49 23 чер 21:13 Mem:KB REAL VIRTUAL VN PAGER SWAP PAGER Tot Share Tot Share Free in out in out Act 106680 13672 316112 27816 1624096 count All 424236 19976 73870680 41352 pages Interrupts Proc:r p d s w Csw Trp Sys Int Sof Flt cow 8190 total 9 80 1541 9 553 555 2 144940 wire 4: sio0 83608 act 14: ata 0.0%Sys 0.0%Intr 0.0%User 0.0%Nice 99.9%Idl 197908 inact 3 16: uhc | | | | | | | | | | 12 cache 19: uhc 1624084 free 20: em1 daefr 23: ehc Namei Name-cache Dir-cache prcfr 3 32: em0 Calls hits % hits % react 196 66: ahd 4 4 100 pdwak 67: ahd zfod pdpgs 1997 cpu0: time Disks da0 da1 pass0 pass1 ozfod intrn 1997 cpu2: time KB/t 0.50 0.00 0.00 0.00 %slo-z 114464 buf 1997 cpu1: time tps 195 0 0 0 tfree 51 dirty 1997 cpu3: time MB/s 0.10 0.00 0.00 0.00 100000 desiredvnodes % busy 100 0 0 0 7750 numvnodes 6193 freevnodes Script output is: 20480+0 records in 20480+0 records out 10485760 bytes transferred in 363.641053 secs (28835 bytes/sec) 20480+0 records in 20480+0 records out 10485760 bytes transferred in 483.640098 secs (21681 bytes/sec) 20480+0 records in 20480+0 records out 10485760 bytes transferred in 483.650721 secs (21680 bytes/sec) 20480+0 records in 20480+0 records out 10485760 bytes transferred in 604.895852 secs (17335 bytes/sec) 20480+0 records in 20480+0 records out 10485760 bytes transferred in 618.500802 secs (16954 bytes/sec) 20480+0 records in 20480+0 records out 10485760 bytes transferred in 618.539979 secs (16952 bytes/sec) 20480+0 records in 20480+0 records out 10485760 bytes transferred in 618.545158 secs (16952 bytes/sec) 20480+0 records in 20480+0 records out 10485760 bytes transferred in 618.553915 secs (16952 bytes/sec) Hmm... My ATA drive does the same almost three times faster... -- [WBR], Arcade.