On 07/01/2012 10:16 PM, Zheng Liu wrote: > On Wed, Jun 27, 2012 at 07:02:45PM -0400, Eric Sandeen wrote: >> On 6/27/12 3:30 PM, Theodore Ts'o wrote: >>> A better workload would be to use a blocksize of 4k. By using a >>> blocksize of 1024k, it's not surprising that the metadata overhead is >>> in the noise. >>> >>> Try something like this; this will cause the extent tree overhead to >>> be roughly equal to the data block I/O. >>> >>> [global] >>> rw=randwrite >>> size=128m >>> filesize=1g >>> bs=4k >>> ioengine=sync >>> fallocate=1 >>> fsync=1 >>> >>> [thread1] >>> filename=testfile > > Hi Eric, > > Could you please run this test with 'journal_async_commit' flag. In my > previous test, this feature can dramatically improve the performance of > uninitialized extent conversion. > > I have sent an email to do a similar test [1]. In that email, I do a > similar test and the journal_async_commit flag quite can improve the > performance. I can try to find time for that, but so far I haven't actually seen any severe impact of conversion on a non-debug kernel. And didn't Jan think that journal_async_commit was fatally flawed? At this point I think it is up to the proponents of the expose-stale-data patch to document & demonstrate the workload which justifies such a change... -Eric > 1. http://comments.gmane.org/gmane.linux.file-systems/63569 > > Regards, > Zheng -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
