Messages in this thread | | | Date | Thu, 8 Jan 2004 12:01:42 +0100 | From | Jan Kasprzak <> | Subject | Re: Fw: Performance drop 2.6.0-test7 -> 2.6.1-rc2 |
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Andrew Morton wrote: : : It would be interesting to run some simple benchmarks (dbench, iozone, : tiobench, etc) on a relatively idle system. : I will try to do, but it is hard to get a "relatively idle" system.
: After that, it'd be a matter of searching through kernel versions, which : you presumably cannot do. Or eliminating device mapper from the picture, : which is also presumably not an option. : I'll try to walk between kernel versions, but I cannot reboot this machine too often ... : : Have you run `hdparm' to check that all those disks have DMA enabled? I : guess they have. : No, I did not run hdparm, but the kernel messages from 2.6.1-rc2 were:
Jan 6 17:05:06 odysseus kernel: Linux version 2.6.1-rc2 (root@atlas) (gcc version 3.2.3 20030422 (Gentoo Linux 1.4 3.2.3-r3, propolice)) #1 Tue Jan 6 16:47:51 CET 2004 [...] Jan 6 17:05:09 odysseus kernel: hda: 40011300 sectors (20485 MB) w/512KiB Cache, CHS=39693/16/63, UDMA(66) Jan 6 17:05:09 odysseus kernel: hda: hda1 hda2 hda3 hda4 < hda5 hda6 > Jan 6 17:05:09 odysseus kernel: hde: max request size: 64KiB Jan 6 17:05:09 odysseus kernel: hde: 150136560 sectors (76869 MB) w/1916KiB Cache, CHS=65535/16/63, UDMA(100) Jan 6 17:05:09 odysseus kernel: hde: hde1 hde2 hde3 Jan 6 17:05:09 odysseus kernel: hdh: max request size: 64KiB Jan 6 17:05:09 odysseus kernel: hdh: 156301488 sectors (80026 MB) w/2048KiB Cache, CHS=65535/16/63, UDMA(100) Jan 6 17:05:09 odysseus kernel: hdh: hdh1 hdh2 hdh3 Jan 6 17:05:09 odysseus kernel: hdi: max request size: 1024KiB Jan 6 17:05:09 odysseus kernel: hdi: 361882080 sectors (185283 MB) w/7965KiB Cache, CHS=22526/255/63, UDMA(100) Jan 6 17:05:09 odysseus kernel: hdi: hdi1 hdi2 hdi3 Jan 6 17:05:09 odysseus kernel: hdj: max request size: 1024KiB Jan 6 17:05:09 odysseus kernel: hdj: 361882080 sectors (185283 MB) w/7965KiB Cache, CHS=22526/255/63, UDMA(100) Jan 6 17:05:09 odysseus kernel: hdj: hdj1 hdj2 hdj3 Jan 6 17:05:09 odysseus kernel: hdk: max request size: 1024KiB Jan 6 17:05:09 odysseus kernel: hdk: 361882080 sectors (185283 MB) w/7965KiB Cache, CHS=22526/255/63, UDMA(100) Jan 6 17:05:09 odysseus kernel: hdk: hdk1 hdk2 hdk3 Jan 6 17:05:09 odysseus kernel: hdl: max request size: 1024KiB Jan 6 17:05:09 odysseus kernel: hdl: 361882080 sectors (185283 MB) w/7965KiB Cache, CHS=22526/255/63, UDMA(100) Jan 6 17:05:09 odysseus kernel: hdl: hdl1 hdl2 hdl3
So judging from the "UDMA(100)" strings I think DMA was enabled then.
Do you think it cannot be something with the read request size? I have never seen a read request >128KB on 2.6.0-test7 (according to average values computed from /proc/diskstats), but in 2.6.1-rc2 I often see bigger requests.
The problem may also be with the IDE controllers. Were there any significant changes between 2.6.0-test7 and 2.6.1-rc2 in this area?
/dev/hda is on the southbridge: 00:04.1 IDE interface: VIA Technologies, Inc. VT82C586/B/686A/B PIPC Bus Master IDE (rev 10)
/dev/hde and /dev/hdh are on CMD680 card: 00:0a.0 RAID bus controller: CMD Technology Inc PCI0680 (rev 02)
others are on the on-board Promise controller: 00:11.0 Unknown mass storage controller: Promise Technology, Inc. 20265 (rev 02)
-Yenya
-- | Jan "Yenya" Kasprzak <kas at {fi.muni.cz - work | yenya.net - private}> | | GPG: ID 1024/D3498839 Fingerprint 0D99A7FB206605D7 8B35FCDE05B18A5E | | http://www.fi.muni.cz/~kas/ Czech Linux Homepage: http://www.linux.cz/ | | I actually have a lot of admiration and respect for the PATA knowledge | | embedded in drivers/ide. But I would never call it pretty:) -Jeff Garzik | - 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/
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