Messages in this thread | | | Date | Thu, 21 Apr 2005 13:30:50 +0200 | From | Andreas Hirstius <> | Subject | Re: Serious performance degradation on a RAID with kernel 2.6.10-bk7 and later |
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Hi,
The fls() patch from David solves the problem :-))
Do you have an idea, when it will be in the mainline kernel??
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 > - 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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