[Lustre-devel] Some investigations on MDS creation rate
Alex.Zhuravlev at Sun.COM
Mon Feb 16 07:26:31 PST 2009
Oleg Drokin wrote:
> I also performed tests on HEAD and it performs significantly worse
> (5.8k at most). Even with all the same fixes ported from b1_6.
> The CPU remains the same and I used lock meter to verify that there
> is no significant lock contention.
> Looking into the oprofile results, it looks like all code just
> became slower (judging by more hits in various areas for the same
> Also some parts of the code are now more heavily loaded (ptlrpc
> +ldlm in HEAD draws more cpu time, llite portion of the code is 50%
> more time
notice HEAD takes two ldlm locks for each create, 1.6 takes one.
> I have no idea why the variability and I do not see anything very
> obvious that would explain sudden overall performance degradation of
> HEAD code either yet.
it would be interesting to gather L1/L2 cache hit/miss with oprofile for
1.6 and HEAD.
More information about the lustre-devel