Messages in this thread | | | Date | Wed, 22 Aug 2012 16:00:25 +1000 | From | NeilBrown <> | Subject | Re: ext4 write performance regression in 3.6-rc1 on RAID0/5 |
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On Wed, 22 Aug 2012 11:57:02 +0800 Yuanhan Liu <yuanhan.liu@linux.intel.com> wrote:
> > -#define NR_STRIPES 256 > +#define NR_STRIPES 1024
Changing one magic number into another magic number might help your case, but it not really a general solution.
Possibly making sure that max_nr_stripes is at least some multiple of the chunk size might make sense, but I wouldn't want to see a very large multiple.
I thing the problems with RAID5 are deeper than that. Hopefully I'll figure out exactly what the best fix is soon - I'm trying to look into it.
I don't think the size of the cache is a big part of the solution. I think correct scheduling of IO is the real answer.
Thanks, NeilBrown
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