Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 9 Nov 2001 18:47:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 9 Nov 2001 18:47:21 -0500 Received: from pdbn-3e36a8eb.pool.mediaWays.net ([62.54.168.235]:25100 "EHLO mail.citd.de") by vger.kernel.org with ESMTP id ; Fri, 9 Nov 2001 18:47:09 -0500 Date: Sat, 10 Nov 2001 00:45:59 +0100 From: Matthias Schniedermeyer To: Erik Andersen , Rik van Riel , Ben Israel , linux-kernel@vger.kernel.org Subject: Re: Disk Performance Message-ID: <20011110004559.A30789@citd.de> In-Reply-To: <20011109155309.A14308@codepoet.org> <20011109162028.A14567@codepoet.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0i In-Reply-To: <20011109162028.A14567@codepoet.org>; from andersen@codepoet.org on Fri, Nov 09, 2001 at 04:20:28PM -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 09, 2001 at 04:20:28PM -0700, Erik Andersen wrote: > On Fri Nov 09, 2001 at 08:57:07PM -0200, Rik van Riel wrote: > > > > > > But wouldn't it make more sense to enable DMA by default, except > > > for a set of blacklisted chipsets, rather then disabling it for > > > everybody just because some older chipsets are crap? > > > > The kernel does this, but only if CONFIG_IDEDMA_AUTO > > is enabled ... > > That seems to be the theory. In practice every system in my house has > that option enabled and yet only some controllers boot up with DMA enabled... > > For example lets look at the following case. This system has > an intel chipset builtin and a Promise PCI card. > > Uniform Multi-Platform E-IDE driver Revision: 6.31 > ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx > PIIX4: IDE controller on PCI bus 00 dev 39 > PIIX4: chipset revision 1 > PIIX4: not 100% native mode: will probe irqs later > ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:DMA, hdb:DMA > ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:DMA, hdd:DMA > PDC20267: IDE controller on PCI bus 00 dev 68 > PCI: Found IRQ 5 for device 00:0d.0 > PDC20267: chipset revision 2 > PDC20267: not 100% native mode: will probe irqs later > ide2: BM-DMA at 0xbc00-0xbc07, BIOS settings: hde:DMA, hdf:DMA > ide3: BM-DMA at 0xbc08-0xbc0f, BIOS settings: hdg:pio, hdh:DMA > hda: IBM-DPTA-373420, ATA DISK drive > hdd: PCRW804, ATAPI CD/DVD-ROM drive > hde: IBM-DTLA-307045, ATA DISK drive > hdg: IBM-DTLA-307045, ATA DISK drive > ide0 at 0x1f0-0x1f7,0x3f6 on irq 14 > ide1 at 0x170-0x177,0x376 on irq 15 > ide2 at 0xac00-0xac07,0xb002 on irq 5 > ide3 at 0xb400-0xb407,0xb802 on irq 5 > hda: 66055248 sectors (33820 MB) w/1961KiB Cache, CHS=4111/255/63, UDMA(33) > hde: 90069840 sectors (46116 MB) w/1916KiB Cache, CHS=89355/16/63 > hdg: 90069840 sectors (46116 MB) w/1916KiB Cache, CHS=89355/16/63 > Partition check: > hda: hda1 hda2 > hde: hde1 > hdg: hdg1 > > So the Intel one came up with DMA enabled, No problem there. > > The Promise controller has two identical 46.1GB IBM-DTLA-307045 7200 > rpm hard drives on it. The controller is capable of ATA100. The hard > drives are capable of ATA100. And yet even with CONFIG_IDEDMA_AUTO > set, these drives both come up running 3.39 MB/s. Here all drives "default" to UDMA: (Kernel is 2.4.9 vanilla) Second Controller is an Promise Ultra 100 TX2 ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx ServerWorks OSB4: IDE controller on PCI bus 00 dev 79 ServerWorks OSB4: chipset revision 0 ServerWorks OSB4: not 100%% native mode: will probe irqs later ide0: BM-DMA at 0xffa0-0xffa7, BIOS settings: hda:DMA, hdb:pio ide1: BM-DMA at 0xffa8-0xffaf, BIOS settings: hdc:pio, hdd:pio PDC20268: IDE controller on PCI bus 02 dev 08 PDC20268: chipset revision 1 PDC20268: not 100%% native mode: will probe irqs later PDC20268: ROM enabled at 0xfebf8000 PDC20268: (U)DMA Burst Bit ENABLED Primary PCI Mode Secondary MASTER Mode. ide2: BM-DMA at 0xef90-0xef97, BIOS settings: hde:pio, hdf:pio ide3: BM-DMA at 0xef98-0xef9f, BIOS settings: hdg:pio, hdh:pio hda: IBM-DTTA-351010, ATA DISK drive hde: IBM-DTLA-307045, ATA DISK drive hdf: IBM-DTLA-307045, ATA DISK drive hdg: WDC WD1000BB-32CCB0, ATA DISK drive ide0 at 0x1f0-0x1f7,0x3f6 on irq 14 ide2 at 0xefe0-0xefe7,0xefae on irq 24 ide3 at 0xefa0-0xefa7,0xefaa on irq 24 hda: 19807200 sectors (10141 MB) w/466KiB Cache, CHS=1232/255/63, UDMA(33) hde: 90069840 sectors (46116 MB) w/1916KiB Cache, CHS=89355/16/63, UDMA(100) hdf: 90069840 sectors (46116 MB) w/1916KiB Cache, CHS=89355/16/63, UDMA(100) hdg: 195371568 sectors (100030 MB) w/2048KiB Cache, CHS=193821/16/63, UDMA(100) Bis denn -- Real Programmers consider "what you see is what you get" to be just as bad a concept in Text Editors as it is in women. No, the Real Programmer wants a "you asked for it, you got it" text editor -- complicated, cryptic, powerful, unforgiving, dangerous. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/