From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 21 Jan 2001 07:25:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 21 Jan 2001 07:25:24 -0500 Received: from zeus.kernel.org ([209.10.41.242]:44490 "EHLO zeus.kernel.org") by vger.kernel.org with ESMTP id ; Sun, 21 Jan 2001 07:25:12 -0500 Date: Sun, 21 Jan 2001 12:44:52 +0100 From: Vojtech Pavlik To: Alan Chandler Cc: Mark Hahn , linux-kernel@vger.kernel.org Subject: Re: [preview] Latest AMD & VIA IDE drivers with UDMA100 support Message-ID: <20010121124452.B804@suse.cz> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from alan@chandlerfamily.org.uk on Sun, Jan 21, 2001 at 10:51:12AM +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 21, 2001 at 10:51:12AM +0000, Alan Chandler wrote: > On Sat, 20 Jan 2001 20:18:34 -0500 (EST), you wrote: > > > >that's not the topic: Andre's talking about pci-clock-based timing > >constants the the driver programs into the ide controller - a matter > >of an extra few/more nanoseconds. > > I know, but when looking hard for a problem in one place and not > finding it, it is sometimes helpful to consider other options. > > I am getting errors under 2.4.0 which didn't appear in 2.2.17 - and as > far as I could see from hdparm - both were at UDMA mode 2 (I assume > thats what the * means - the man page wasn't very clear). My drives > only handle up to this mode, and I was wondering if the new driver was > trying to run them at a mode higher than they were supposed to go. > > This massive difference in timing seemed significant. No, but to me it seems that even though UDMA2 mode is selected in the drive in 2.2.17 (that's what the * means), the kernel doesn't use DMA, and thus everything works in PIO4. This would well explain the speed difference. > >quite slow in either case, at least for modern hardware (which is > >all in the 20-40 MB/s range). this looks like a PIO vs DMA difference > >to me, not even UDMA. of course, hdparm can tell you what mode you're in. > > I did discover a difference - 2.2.17 set the drives with multisector > off, 2.4.0 was setting multisector on. Multisector is valid only in PIO modes. If both were doing some kind of DMA, it wouldn't change anything. > However, I have redone the > timing with multisector turned on in the 2.2.17 case and the > difference is still there. > > Under 2.2.17 with multisector turned on > > > /dev/hda: > > Model=IBM-DHEA-38451, FwRev=HP8OA20C, SerialNo=SH0SH0X1795 > Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs } > RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=28 > BuffType=3(DualPortCache), BuffSize=472kB, MaxMultSect=16, > MultSect=16 > DblWordIO=no, OldPIO=2, DMA=yes, OldDMA=2 > CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=16514064 > tDMA={min:120,rec:120}, DMA modes: sword0 sword1 sword2 mword0 mword1 > mword2 > IORDY=on/off, tPIO={min:240,w/IORDY:120}, PIO modes: mode3 mode4 > UDMA modes: mode0 mode1 *mode2 > > ------------------ > > /dev/hda: > Timing buffered disk reads: 64 MB in 19.88 seconds = 3.22 MB/sec > > > Under 2.4.0 > > > /dev/hda: > > Model=IBM-DHEA-38451, FwRev=HP8OA20C, SerialNo=SH0SH0X1795 > Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs } > RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=28 > BuffType=3(DualPortCache), BuffSize=472kB, MaxMultSect=16, > MultSect=16 > DblWordIO=no, OldPIO=2, DMA=yes, OldDMA=2 > CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=16514064 > tDMA={min:120,rec:120}, DMA modes: sword0 sword1 sword2 mword0 mword1 > mword2 > IORDY=on/off, tPIO={min:240,w/IORDY:120}, PIO modes: mode3 mode4 > UDMA modes: mode0 mode1 *mode2 > > ------------------ > > /dev/hda: > Timing buffered disk reads: 64 MB in 6.58 seconds = 9.73 MB/sec > > > > I don't suppose the fact that my hdparm is oldish (3.6 I think) have > any bearing on this? No, 3.6 is OK I think. -- Vojtech Pavlik SuSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/