On Mon, 2009-03-23 at 18:36 +0100, root wrote: > Package: linux-image-2.6.26-1-686 > Version: 2.6.26-13lenny2 > Severity: important > > > I have 450NX server board (two cpu Xeon II 450MHz). My ide controler is PIIX4. > > I found that after update to lenny's 2.6.26-1-xen-686 IDE performance droped > to just 1.50MB/s (hdparm -t). With 2.6.18-6-xen-686 I had 21.54 MB/s. > (Tested both in -xen-686 and -686, in signle user). Performance > of scsi disc's doesn't changed. [...] > [ 4.054227] piix: 450NX errata present, disabling IDE DMA. > [ 4.054433] piix: A BIOS update may resolve this. > [ 4.056035] PIIX4: IDE controller (0x8086:0x7111 rev 0x01) at PCI slot > 0000:00:0c.1 > [ 4.056051] PIIX4: not 100% native mode: will probe irqs later > [ 4.056051] PIIX4: IDE port disabled > [ 4.056051] ide0: BM-DMA at 0x2c20-0x2c27 > [ 4.056757] Probing IDE interface ide0... > [ 4.349476] hda: IBM-DTLA-307030, ATA DISK drive > [ 5.021402] hda: host max PIO4 wanted PIO255(auto-tune) selected PIO4 > [ 5.021674] hda: no DMA mode selected > [ 5.021888] hda: host max PIO4 wanted PIO255(auto-tune) selected PIO4 [...] > So it looks like there is some blacklist (in piix modules) for this server > board, > and kernel uses generic (and non-dma) module for ide. But with 2.6.18-686 it > was working.
However, this blacklist has been present since before Linux 2.6.12, so it doesn't really explain the change. > Additionally I probably have newset BIOS possible. > > Mayby this is because of broken write cache flushing? [...] What do you mean? > As far as I know rev 03 is blacklisted for some reason. Is there a way to > force > dma? I expect that you can do this using hdparm, but I wouldn't recommend it. Ben. -- Ben Hutchings It is impossible to make anything foolproof because fools are so ingenious.
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