On Sunday, March 03, 2002 10:46:18 PM -0700 Andreas Dilger <[EMAIL PROTECTED]>
wrote:
> On Mar 04, 2002 00:32 -0500, Chris Mason wrote:
>> Ok, I'm not going to be able to replicate the entire test, but I can
>> at least demonstrate the high number of subdirectories is slowing down
>> the creation time. I'm guessing it is either caused by the
>> subdirectory inodes not being in cache often enough, or increased
>> log traffic.
>>
>> Try setting the number of subdirectories to 10. If this fixes the
>> reiserfs performance problem, we can look into solutions.
>
> Hmm, interesting. When Andrew was doing MTA performance testing on
> ext3, he found that _increasing_ the number of directories improved
> performance. I don't have the thread handy, but I _think_ it had to
> do with VFS locking on the directories - more directories means that
> more operations can be done in parallel since Al made this part of
> the VFS thread-safe.
Very true, you should be able to see the locking issue with a
multiprocess benchmarking. But, it probably helps less and less
as the number of directories grows over the number of writers.
-chris
