[Lustre-devel] Some investigations on MDS creation rate

[Oleg Drokin]

Hello!

On Feb 16, 2009, at 10:26 AM, Alex Zhuravlev wrote:

> 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   
>> workload).
>>   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.

What is the other one? I am looking at mdt_md_create and I see it  
locks parent, but not child, just like b1_6.

Bye,
     Oleg