Messages in this thread | | | Date | Fri, 08 Dec 2006 13:34:58 +0800 | From | Bob <> | Subject | Re: Kernel 2.6 SMP very slow with ServerWorks LE Chipset |
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Alan wrote: >> As a test of raw CPU power I've been decompressing the kernel tree, with >> a UP 2.6 kernel this takes about 1m 15s, I don't know if bz2 is >> multithreaded but even if it's not I would expect a slight speed increase >> but in fact with a SMP 2.6 kernel it take 13 ~ 26m, with a SMP 2.4 >> kernel it takes 1m 28s and with a 2.4 UP 1m 35s. > > The 2.4 numbers look correct (slightly slower), the 2.6 numbers do not. > > > Nothing obviously wrong from the traces however. If you pin the bzip to a > given processor do you get different results according to which CPU ? > > (see man taskset for info on the commands) > > If you get very different times on the two processors that will be very > useful information.
Mmm CPU 0 in 1m 32s, but I was running things like ps and taskset in another terminal to verify affinity, CPU 1 still hadn't finished in 40m when I killed it. I've downloaded the LFDK mentioned in the other post and will post the results when I have them.
Thanks for replying,
This is the script I'm using to time decompression nas:~# cat ./cputest.sh date taskset -c 1 nice -n -8 tar -xjf /root/linux-2.6.18.1.tar.bz2 date uname -a rm -r /root/linux-2.6.18.1/ nas:~#
both the tar and bzip2 processes have their affinity and priority set by the above command. - 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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