From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [git patches] IDE update Date: Thu, 7 Jul 2005 15:48:13 +0200 Message-ID: <58cb370e05070706485276333@mail.gmail.com> References: <200507042033.XAA19724@raad.intranet> <42C9C56D.7040701@tomt.net> <42CA5A84.1060005@rainbow-software.org> <20050705101414.GB18504@suse.de> <42CA5EAD.7070005@rainbow-software.org> <42CC4589.8060509@tmr.com> Reply-To: Bartlomiej Zolnierkiewicz Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from nproxy.gmail.com ([64.233.182.203]:7785 "EHLO nproxy.gmail.com") by vger.kernel.org with ESMTP id S261551AbVGGNsO convert rfc822-to-8bit (ORCPT ); Thu, 7 Jul 2005 09:48:14 -0400 Received: by nproxy.gmail.com with SMTP id o25so52885nfa for ; Thu, 07 Jul 2005 06:48:13 -0700 (PDT) In-Reply-To: <42CC4589.8060509@tmr.com> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Bill Davidsen Cc: Ondrej Zary , =?ISO-8859-1?Q?Andr=E9_Tomt?= , Al Boldi , Linus Torvalds , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org On 7/6/05, Bill Davidsen wrote: > Ondrej Zary wrote: > > Jens Axboe wrote: > > > >> On Tue, Jul 05 2005, Ondrej Zary wrote: > >> > >>> Andr=E9 Tomt wrote: > >>> > >>>> Al Boldi wrote: > >>>> > >>>> > >>>>> Bartlomiej Zolnierkiewicz wrote: { > >>>>> > >>>>> > >>>>>>>> On 7/4/05, Al Boldi wrote: > >>>>>>>> Hdparm -tT gives 38mb/s in 2.4.31 > >>>>>>>> Cat /dev/hda > /dev/null gives 2% user 33% sys 65% idle > >>>>>>>> > >>>>>>>> Hdparm -tT gives 28mb/s in 2.6.12 > >>>>>>>> Cat /dev/hda > /dev/null gives 2% user 25% sys 0% idle 73% I= OWAIT > >>>> > >>>> > >>>> > >>>> The "hdparm doesn't get as high scores as in 2.4" is a old discu= ssed > >>>> to death "problem" on LKML. So far nobody has been able to show = it > >>>> affects anything but that pretty useless quasi-benchmark. > >>>> > >>> > >>> No, it's not a problem with hdparm. hdparm only shows that there = is > >>> _really_ a problem: > >>> > >>> 2.6.12 > >>> root@pentium:/home/rainbow# time dd if=3D/dev/hda of=3D/dev/null = bs=3D512 > >>> count=3D1048576 > >>> 1048576+0 records in > >>> 1048576+0 records out > >>> > >>> real 0m32.339s > >>> user 0m1.500s > >>> sys 0m14.560s > >>> > >>> 2.4.26 > >>> root@pentium:/home/rainbow# time dd if=3D/dev/hda of=3D/dev/null = bs=3D512 > >>> count=3D1048576 > >>> 1048576+0 records in > >>> 1048576+0 records out > >>> > >>> real 0m23.858s > >>> user 0m1.750s > >>> sys 0m15.180s > >> > >> > >> > >> Perhaps some read-ahead bug. What happens if you use bs=3D128k for > >> instance? > >> > > Nothing - it's still the same. > > > > root@pentium:/home/rainbow# time dd if=3D/dev/hda of=3D/dev/null bs= =3D128k > > count=3D4096 > > 4096+0 records in > > 4096+0 records out > > > > real 0m32.832s > > user 0m0.040s > > sys 0m15.670s > > > Why is the system time so high? I tried that test here, and got: >=20 > oddball:root> time dd if=3D/dev/hda of=3D/dev/null bs=3D128k count=3D= 4096 > 4096+0 records in > 4096+0 records out >=20 > real 0m37.927s > user 0m0.025s > sys 0m6.547s > oddball:root> uname -rn > oddball.prodigy.com 2.6.11ac7 >=20 > Now this is one of the slowest CPUs still in use (which I why I test > responsiveness on it), and it uses far less CPU time. > cat /proc/cpuinfo > processor : 0 > vendor_id : GenuineIntel > cpu family : 6 > model : 5 > model name : Pentium II (Deschutes) > stepping : 1 > cpu MHz : 348.507 > cache size : 512 KB > fdiv_bug : no > hlt_bug : no > f00f_bug : no > coma_bug : no > fpu : yes > fpu_exception : yes > cpuid level : 2 > wp : yes > flags : fpu vme de tsc msr pae mce cx8 apic sep mtrr pge mc= a > cmov pat pse36 mmx fxsr > bogomips : 686.08 >=20 >=20 > The first post said it felt like running PIO, it certainly is using C= PU > like it as well. >=20 > Now here's some dmesg from this system... >=20 > PIIX4: IDE controller at PCI slot 0000:00:07.1 > PIIX4: chipset revision 1 > PIIX4: not 100% native mode: will probe irqs later > ide0: BM-DMA at 0x1080-0x1087, BIOS settings: hda:DMA, hdb:pio > ide1: BM-DMA at 0x1088-0x108f, BIOS settings: hdc:DMA, hdd:pio > Probing IDE interface ide0... > hda: Maxtor 90845D4, ATA DISK drive > hdb: WDC AC31600H, ATA DISK drive > hdb: Disabling (U)DMA for WDC AC31600H (blacklisted) > ide0 at 0x1f0-0x1f7,0x3f6 on irq 14 > Probing IDE interface ide1... > hdc: NEC CD-ROM DRIVE:28C, ATAPI CD/DVD-ROM drive > ide1 at 0x170-0x177,0x376 on irq 15 > hda: max request size: 128KiB > hda: 16514064 sectors (8455 MB) w/512KiB Cache, CHS=3D16383/16/63, UD= MA(33) > hda: cache flushes not supported > hda: hda1 hda2 hda3 hda4 < hda5 > > hdb: max request size: 128KiB > hdb: 3173184 sectors (1624 MB) w/128KiB Cache, CHS=3D3148/16/63 > hdb: cache flushes not supported > hdb: hdb1 hdb2 hdb3 > hdc: ATAPI 32X CD-ROM drive, 128kB Cache, UDMA(33) > Uniform CD-ROM driver Revision: 3.20 >=20 >=20 > And indeed it does show hda as dma, and hdb as pio (older versions of > the kernel let me set hdb to dma and it worked fine...). But in the > posted demsg the BIOS settings show pio for hda. Is this in any way > relevant, given that UDA(33) appears later? BIOS setting is irrelevant and ~14MB/s for UDMA33 is OK. CPU cycles are wasted somewhere else...