Messages in this thread | | | From | David Mosberger <> | Date | Thu, 21 Apr 2005 08:05:22 -0700 | Subject | Re: [Gelato-technical] Re: Serious performance degradation on a RAID with kernel 2.6.10-bk7 and later |
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Tony and Andrew,
I just checked 2.6.12-rc3 and the fls() fix is indeed missing. Do you know what happened?
--david
>>>>> On Thu, 21 Apr 2005 13:30:50 +0200, Andreas Hirstius <Andreas.Hirstius@cern.ch> said:
Andreas> Hi, The fls() patch from David solves the problem :-))
Andreas> Do you have an idea, when it will be in the mainline Andreas> kernel??
Andreas> Andreas
Andreas> Bartlomiej ZOLNIERKIEWICZ wrote:
>> Hi! >> >>> A small update. >>> >>> Patching mm/filemap.c is not necessary in order to get the >>> improved performance! It's sufficient to remove >>> roundup_pow_of_two from |get_init_ra_size ... >>> >>> So a simple one-liner changes to picture dramatically. But why >>> ?!?!? >> >> >> roundup_pow_of_two() uses fls() and ia64 has buggy fls() >> implementation [ seems that David fixed it but patch is not in >> the mainline yet]: >> >> http://www.mail-archive.com/linux-ia64@vger.kernel.org/msg01196.html >> >> That would also explain why you couldn't reproduce the problem on >> ia32 Xeon machines. >> >> Bartlomiej >>
Andreas> _______________________________________________ Andreas> Gelato-technical mailing list Andreas> Gelato-technical@gelato.unsw.edu.au Andreas> https://www.gelato.unsw.edu.au/mailman/listinfo/gelato-technical - 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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