Messages in this thread | | | Date | Thu, 20 Dec 2001 09:40:25 -0800 | From | William Lee Irwin III <> | Subject | Re: Poor performance during disk writes |
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On Thu, Dec 20, 2001 at 02:27:17PM +0100, Dieter N?tzel wrote: > Amen.. > Sorry, Helge sure you are right in theory but try dbench 32 (maybe > bonnie/bonnie++) and playing an MP3/Ogg-Vorbis in parallel... > That's my first test on any "new" kernel version. > > Even with an 1 GHz Athlon II, 640 MB, U160 DDYS 18 GB, 10k IBM disk (on an > AHA-2940UW) it stutters like mad. I am running all my kernel _with_ Robert > Love's preempt + lock-break patches and it doesn't solve the problem. > CPU load is (very) low but it do not work like it should.
I tried this on my 600MHz Athlon with 768MB of RAM and U160 DDYS 36GB 10Krpm IBM disk on a Adaptect 39160 I managed to get it not to stutter at all. I was also using preempt + lockbreak and a few others. The crucial patch appeared to be from Andrew Morton and it involved tuning the elevator to avoid read starvation. A significantly helpful hardware suggestion regarding the sound card and drivers came from Linus himself, though.
Linus and others pointed out that applications are able to cause some drivers to generate a large number of interrupts by using small buffers and unfriendly ioctl's, especially esd. My workaround was to change out sound hardware and disable esd. If this is happening to you, /proc/profile should show handle_IRQ_event() and schedule() very high up. On the other hand, this shows up as a steady drain on system resources and excessive system time, not stuttering or skipping.
Andrew, I don't have the URL for that still floating around. Can you point Dieter to it?
Cheers, Bill - 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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