Re: [PATCH 00/26] AIO performance improvements/cleanups, v2

From: Jens Axboe
Date: Fri Dec 14 2012 - 02:36:11 EST


On 2012-12-14 03:26, Jack Wang wrote:
> 2012/12/14 Jens Axboe <jaxboe@xxxxxxxxxxxx>:
>> On Mon, Dec 03 2012, Kent Overstreet wrote:
>>> Last posting: http://thread.gmane.org/gmane.linux.kernel.aio.general/3169
>>>
>>> Changes since the last posting should all be noted in the individual
>>> patch descriptions.
>>>
>>> * Zach pointed out the aio_read_evt() patch was calling functions that
>>> could sleep in TASK_INTERRUPTIBLE state, that patch is rewritten.
>>> * Ben pointed out some synchronize_rcu() usage was problematic,
>>> converted it to call_rcu()
>>> * The flush_dcache_page() patch is new
>>> * Changed the "use cancellation list lazily" patch so as to remove
>>> ki_flags from struct kiocb.
>>
>> Kent, I ran a few tests, and the below patches still don't seem as fast
>> as the approach I took. To keep it fair, I used your aio branch and
>> applied by dio speedups too. As a sanity check, I ran with your branch
>> alone as well. The quick results below - kaio is kent-aio, just your
>> branch. kaio-dio is with the direct IO speedups too. jaio is my branch,
>> which already has the dio changes too.
>>
>> Devices Branch IOPS
>> 1 kaio ~915K
>> 1 kaio-dio ~930K
>> 1 jaio ~1220K
>> 6 kaio ~3050K
>> 6 kaio-dio ~3080K
>> 6 jaio 3500K
>>
>> The box runs out of CPU driving power, which is why it doesn't scale
>> linearly, otherwise I know that jaio at least does. It's basically
>> completion limited for the 6 device test at the moment.
>>
>> I'll run some profiling tomorrow morning and get you some better
>> results. Just thought I'd share these at least.
>>
>> --
>> Jens Axboe
>>
>
> A really good performance, woo.
>
> I think the device tested is really fast PCIe SSD builded by fusionio
> with fusionio in house block driver?

It is pci-e flash storage, but it is not fusion-io.

> any compare number with current mainline?

Sure, I should have included that. Here's the table again, this time
with mainline as well.

Devices Branch IOPS
1 mainline ~870K
1 kaio ~915K
1 kaio-dio ~930K
1 jaio ~1220K
6 kaio ~3050K
6 kaio-dio ~3080K
6 jaio ~3500K
6 mainline ~2850K


--
Jens Axboe

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