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SubjectRe: [Lse-tech] [PATCH] New dcache / inode hash tuning patch
>> It actually seems a fraction slower (see systimes for Kernbench-16,
>> for instance).
>
> Can you play a bit with the hash table sizes? Perhaps double the
> dcache hash and half the inode hash ?

I quadrupled the dcache hash size ... helped a bit. Is still a little
slower, which I don't understand ... your plan should make it go faster,
AFAICS. Those off-node accesses to ZONE_NORMAL are really expensive for me.

Kernbench-2: (make -j N vmlinux, where N = 2 x num_cpus)
Elapsed User System CPU
2.5.62-mjb3 44.24 558.12 94.17 1473.83
2.5.62-mjb3-andi 44.28 557.90 95.79 1475.67
2.5.62-mjb3-andi-4x 44.20 557.96 94.77 1475.83

Kernbench-16: (make -j N vmlinux, where N = 16 x num_cpus)
Elapsed User System CPU
2.5.62-mjb3 45.19 560.95 114.77 1495.00
2.5.62-mjb3-andi 45.39 561.29 117.73 1495.67
2.5.62-mjb3-andi-4x 45.34 560.54 116.85 1493.50

> I suspect it really just needs a better hash function. I'll cook
> something up based on FNV hash.

Sounds good ;-)

M.

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