From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ondrej Zary Subject: Re: [git patches] IDE update Date: Thu, 07 Jul 2005 15:47:08 +0200 Message-ID: <42CD325C.9090505@rainbow-software.org> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <42CC4589.8060509@tmr.com> Sender: linux-kernel-owner@vger.kernel.org To: Bill Davidsen Cc: =?ISO-8859-1?Q?Andr=E9_Tomt?= , Al Boldi , 'Bartlomiej Zolnierkiewicz' , 'Linus Torvalds' , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-ide@vger.kernel.org Bill Davidsen wrote: > Ondrej Zary wrote: >=20 >> 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% IO= WAIT >>>>> >>>>> >>>>> >>>>> >>>>> The "hdparm doesn't get as high scores as in 2.4" is a old=20 >>>>> discussed to death "problem" on LKML. So far nobody has been able= =20 >>>>> to show it affects anything but that pretty useless quasi-benchm= ark. >>>>> >>>> >>>> No, it's not a problem with hdparm. hdparm only shows that there i= s=20 >>>> _really_ a problem: >>>> >>>> 2.6.12 >>>> root@pentium:/home/rainbow# time dd if=3D/dev/hda of=3D/dev/null b= s=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 b= s=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=3D= 128k=20 >> 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=20 > 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=20 > 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=20 > 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= =20 > the kernel let me set hdb to dma and it worked fine...). But in the=20 > posted demsg the BIOS settings show pio for hda. Is this in any way=20 > relevant, given that UDA(33) appears later? I've had AC31600H drive too and it used to run fine in DMA mode for age= s=20 (at least in Windows). No idea why it is blacklisted. >=20 > Ondrei: >=20 > PIIX4: IDE controller at PCI slot 00:07.1 > PIIX4: chipset revision 1 > PIIX4: not 100% native mode: will probe irqs later > ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:pio, hdb:pio > ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:pio, hdd:pio > hda: WDC WD300BB-00AUA1, ATA DISK drive > blk: queue c03b3360, I/O limit 4095Mb (mask 0xffffffff) > hdd: MSI CD-RW MS-8340S, ATAPI CD/DVD-ROM drive > ide0 at 0x1f0-0x1f7,0x3f6 on irq 14 > ide1 at 0x170-0x177,0x376 on irq 15 > hda: attached ide-disk driver. > hda: host protected area =3D> 1 > hda: 58633344 sectors (30020 MB) w/2048KiB Cache, CHS=3D3649/255/63, = UDMA(33) >=20 >=20 > Unless Ondrei's CPU is slower than a PI-350, maybe it is running pio = for=20 > some reason, in spite of hdparm -i showing udma2 mode. >=20 > I just mentioned it because the CPU usage doesn't seem compatible wit= h=20 > DMA operation. >=20 Yes, the CPU is slower. It's Cyrix MII PR300 (225MHz): root@pentium:/home/rainbow# cat /proc/cpuinfo processor : 0 vendor_id : CyrixInstead cpu family : 6 model : 2 model name : M II 3x Core/Bus Clock stepping : 4 cpu MHz : 225.004 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu de tsc msr cx8 pge cmov mmx cyrix_arr bogomips : 448.92 With PIO, it's much slower. --=20 Ondrej Zary