On 2011-04-18 20:32, Bart Van Assche wrote:
> On Mon, Apr 18, 2011 at 8:28 PM, Jens Axboe <jaxboe@xxxxxxxxxxxx> wrote:
>> On 2011-04-18 20:21, Bart Van Assche wrote:
>>> a performance regression in the block layer not related to the md
>>> issue. If I run a small block IOPS test on a block device created by
>>> ib_srp (NOOP scheduler) I see about 11% less IOPS than with 2.6.38.3
>>> (155.000 IOPS with 2.6.38.3 and 140.000 IOPS with 2.6.39-rc3+).
>>
>> That's not good. What's the test case?
>
> Nothing more than a fio IOPS test:
>
> fio --bs=512 --ioengine=libaio --buffered=0 --rw=read --thread
> --iodepth=64 --numjobs=2 --loops=10000 --group_reporting --size=1G
> --gtod_reduce=1 --name=iops-test --filename=/dev/${dev} --invalidate=1
Interesting, I'll have to check if we regressed with all these recent
changes. Comparing your .38 to .39-rc3+, are you using more/less CPU,
more/less sys%, etc?
A quick perf record -fg / perf report -g for both kernels would be nice
to see.
--
Jens Axboe
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