Re: [PATCH v3 3/4] block: loop: use kthread_work

From: Ming Lei
Date: Thu May 07 2015 - 06:32:11 EST


On Thu, May 7, 2015 at 3:17 PM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> On Thu, May 07, 2015 at 01:08:25AM +0800, Ming Lei wrote:
>> The following patch will use dio/aio to submit IO to backing file,
>> then it isn't good to schedule IO concurrently from work, so
>> use kthread_work.
>
> I can't really parse this, what's the specific advantage here?

Patch 4's commit log provides the test data.

>From the data, it is observed that one thread is enough to get
similar throughput with previous one which submits IO from
work concurrently.

Single thread can decrease context switch a lots, also one thread is
often used to submit AIO in reality.

Thanks,
Ming Lei
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