Messages in this thread | | | Date | Sat, 03 Apr 2004 13:24:21 +0200 | From | Andreas Hartmann <> | Subject | Re: 2.6.4 : 100% CPU use on EIDE disk operarion, VIA chipset |
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Mikhail Ramendik wrote: > Hello, > > I have an computer with an AMD Duron, and the motehrboard chipset is VIA > KT133. The hard drive is a Seagate Barracuda 7200.7 ; no other EIDE > devices are attached. > > I run an RH9-based distro, and added a 2.6.4 kernel to it. The following > problem was tested with two kernel variants: 2.6.4+wolk2/0 with > preeemption enabled, and 2.6.4 plain from kernel.org with preemption > disabled. No difference. > > I noticed performance problems with 2.6.4, and tracked them to strange > HDD behavior. > > It turned out that on disk-intensive operation, the "system" CPU usage > skyrockets. With a mere "cp" of a large file to the same direstory > (tested with ext3fs and FAT32 file systems), it is 100% practically all > of the time !
Which tool do you use for measure? xosview?
I'm having here the same problem. But it depends on the tool which is used for measuring. If I use top from procps 3.2, I can't see this high system load. "time" can't see it, too.
This is what top says during cp of 512MB-file: Cpu(s): 2.0% us, 8.3% sy, 0.0% ni, 0.0% id, 89.0% wa, 0.7% hi, 0.0% si
New is "wa", what probably means "wait". This value is very high as long as the HD is writing or reading datas:
cp dummy /dev/null produces this top-line: Cpu(s): 3.0% us, 5.3% sy, 0.0% ni, 0.0% id, 91.0% wa, 0.7% hi, 0.0% si
and time says: real 0m53.195s user 0m0.013s sys 0m2.124s
But you're right, 2.6.4 is slower than 2.4.25. See the thread "Very poor performance with 2.6.4" here in the list.
Regards, Andreas Hartmann - 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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