On Mon 02-07-12 11:33:33, Eric Sandeen wrote:

On 07/01/2012 10:16 PM, Zheng Liu wrote:

quoted

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?

  Yes, that option is broken and basically unfixable for data=ordered mode
(see http://comments.gmane.org/gmane.comp.file-systems.ext4/30727). For
data=writeback it works fine AFAICT.

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR