Messages in this thread | | | From | Jeff Moyer <> | Subject | Re: [PATCH] AIO: Don't plug the I/O queue in do_io_submit() | Date | Tue, 13 Dec 2011 17:18:41 -0500 |
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Dave Kleikamp <dave.kleikamp@oracle.com> writes:
> Asynchronous I/O latency to a solid-state disk greatly increased > between the 2.6.32 and 3.0 kernels. By removing the plug from > do_io_submit(), we observed a 34% improvement in the I/O latency. > > Unfortunately, at this level, we don't know if the request is to > a rotating disk or not.
I'm guessing I know the answer to this, but what workload were you testing, and can you provide more concrete evidence than "latency greatly increased?" Also, have you tested the effects this has when using traditional storage for whatever your workload is? I don't feel comfortable essentially reverting a performance patch without knowing the entire picture. I will certainly do some testing on my end, too.
Cheers, Jeff
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