From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964996AbWDHPeG (ORCPT ); Sat, 8 Apr 2006 11:34:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964994AbWDHPeF (ORCPT ); Sat, 8 Apr 2006 11:34:05 -0400 Received: from zproxy.gmail.com ([64.233.162.202]:1038 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S964996AbWDHPeD convert rfc822-to-8bit (ORCPT ); Sat, 8 Apr 2006 11:34:03 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=pQP9ga2HXSY2SfDLsnM1jGRywfKD795pBgwv63DuKPc+EkCOtkTp0RV7yrtD5Mxg9lGbZYvauBF7q8cX87cMUsww/ucr6zdUX5RXiDqfvrLNFXwZN2Wvv/6ai8vvxHcTj84ZRk5Lv8YeQdyHBOCJQV+eTXyLLluwQWIgGXCHV3Q= Message-ID: <5a4c581d0604080834k7961aff5l7794b8893325a90c@mail.gmail.com> Date: Sat, 8 Apr 2006 17:34:00 +0200 From: "Alessandro Suardi" To: "Linux Kernel" Subject: Re: 40% IDE performance regression going from FC3 to FC5 with same kernel In-Reply-To: <5a4c581d0604080747w61464d48k5480391d98b2bc47@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <5a4c581d0604080747w61464d48k5480391d98b2bc47@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 4/8/06, Alessandro Suardi wrote: > I'll be filing a FC5 performance bug for this but would like an opinion > from the IDE kernel people just in case this has already been seen... > > I just upgraded my home K7-800, 512MB RAM box from FC3 to FC5 > and noticed a disk performance slowdown while copying files around. > > System has two 160GB disks, a Samsung SP1604N 2MB cache and > a Maxtor 6Y160P0 8MB cache; both disks appear to be almost 2x > slower both on hdparm -t tests (17-19MB/s against 33/35 MB/s) and > on dd tests, like this: > > FC3 > [root@donkey tmp]# time dd if=/dev/hda of=/dev/null skip=200 bs=1024k count=200 > 200+0 records in > 200+0 records out > > real 0m4.623s > user 0m0.004s > sys 0m1.308s > > FC5 > [root@donkey tmp]# time dd if=/dev/hda of=/dev/null skip=200 bs=1024k count=200 > 200+0 records in > 200+0 records out > 209715200 bytes (210 MB) copied, 9.67808 seconds, 21.7 MB/s > > real 0m9.683s > user 0m0.008s > sys 0m1.400s > > > The initial tests were my last FC3 self-compiled kernel (2.6.16-rc5-git8) > vs FC5's 2.6.16-1.2080_FC5 kernel; so just to be sure, I copied over > from my FC3 partition the 2.6.16-rc5-git8 kernel and its config file, > and rebuilt it under FC5, with just a few differences for the new USB > 2.0 disk I added to a PCI controller I just put in, namely > > [root@donkey linux-2.6.16-rc5-git8]# diff .config > /fc3/usr/src/linux-2.6.16-rc5-git8/.config > 4c4 > < # Fri Apr 7 03:58:23 2006 > --- > > # Mon Mar 6 22:49:32 2006 > 1110,1112c1110 > < CONFIG_USB_EHCI_HCD=m > < CONFIG_USB_EHCI_SPLIT_ISO=y > < CONFIG_USB_EHCI_ROOT_HUB_TT=y > --- > > # CONFIG_USB_EHCI_HCD is not set > 1115c1113 > < CONFIG_USB_UHCI_HCD=m > --- > > CONFIG_USB_UHCI_HCD=y > 1218d1215 > < # CONFIG_USB_SISUSBVGA is not set > > The result is unexpected - performance delta is still there. Concatenating > output from hdparm -i /dev/hda and hdparm /dev/hda for the same kernel > under FC3 and FC5, the only difference is > > [root@donkey ~]# diff /tmp/hdparm.out.2616rc2git8-fc5 > /tmp/hdparm.out.2616rc2git8 > 14c14 > < Drive conforms to: (null): ATA/ATAPI-1 ATA/ATAPI-2 ATA/ATAPI-3 > ATA/ATAPI-4 ATA/ATAPI-5 ATA/ATAPI-6 ATA/ATAPI-7 > --- > > Drive conforms to: (null): > 27c27 > < geometry = 19457/255/63, sectors = 312581808, start = 0 > --- > > geometry = 19457/255/63, sectors = 160041885696, start = 0 > > I'll try now and rebuild a 2.6.16-rc5-git8 kernel under FC5 with the > FC3 GCC and see whether that is responsible for the performance > drop... of course if anyone has any idea about what's going on, I > will be happy to try out stuff. Attaching hdparm output from the FC5 > 2.6.16-rc5-git8 just to show that there is DMA etc. all configured fine. Just for the record - no, even rebuilding same kernel with same GCC (3.4.4) under FC5, disk performance is much slower than FC3 - according to hdparm _and_ dd tests. --alessandro "Dreamer ? Each one of us is a dreamer. We just push it down deep because we are repeatedly told that we are not allowed to dream in real life" (Reinhold Ziegler)