Re: [PATCH 1/2] ext4: Calculate and verify inode checksums

[Joel Becker]

On Thu, Apr 07, 2011 at 10:10:52AM -0700, Sunil Mushran wrote:
> On 04/07/2011 09:40 AM, Darrick J. Wong wrote:
> >That said, I haven't really quantified the performance impact of this naive
> >approach yet, so I wonder -- did you see a similar scenario with ocfs2, and
> >what kind of performance increase did you get by adapting the code to use the
> >jbd2 trigger?  If there's potentially a large increase, it would be interesting
> >to apply the same conversion to the group descriptor checksumming code too.
> 
> Joel Becker may remember the overhead. He wrote the patch. That said we have few
> differences. ocfs2 has larger (blocksized) inodes. Also, it computes ECC. The code
> is in fs/ocfs2/blockcheck.c.

	ocfs2 does the journal access/journal dirty cycle a lot more
than extN.  I think you'd want to generate your own numbers.

Joel


-- 

"Conservative, n.  A statesman who is enamoured of existing evils,
 as distinguished from the Liberal, who wishes to replace them
 with others."
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			http://www.jlbec.org/
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