Messages in this thread | | | Date | Tue, 11 May 2004 13:22:05 -0700 | From | Andrew Morton <> | Subject | Re: dentry bloat. |
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Maneesh Soni <maneesh@in.ibm.com> wrote: > > We can see this happening in the following numbers taken using dcachebench* > gathered on 2-way P4 Xeon 2.4MHz SMP box with 4.5GB RAM. The benchmark was run > with the following parameters and averaged over 10 runs. > ./dcachebench -p 32 -b testdir > > Average microseconds/iterations Std. Deviation > (lesser is better) > 2.6.6 10204 161.5 > 2.6.6-mm1 10571 51.5 >
Well.. this could be anything. If the hash is any good -mm shouldn't be doing significantly more locked operations. (I think - didn't check very closely).
Also the inode and dentry hash algorithms were changed in -mm. You can evaluate the effect of that by comparing 2.6.6 with current Linus -bk.
If we compare 2.6.6-bk with 2.6.6-mm1 and see a slowdown on SMP and no slowdown on UP then yup, it might be due to additional locking.
But we should evaluate the hash changes separately.
Summary:
2.6.6-rc3: baseline 2.6.6: dentry size+alignment changes 2.6.6-bk: dentry size+alignment changes, hash changes 2.6.6-mm1: dentry size+alignment changes, hash changes, lots of other stuff. - 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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