Re: serial percpu_ref draining in exit_aio()

From: Jeff Moyer
Date: Fri Mar 20 2015 - 14:56:20 EST


Jens Axboe <axboe@xxxxxxxxx> writes:

> On 03/19/2015 03:27 PM, Jens Axboe wrote:
>> On 03/19/2015 03:00 PM, Tejun Heo wrote:
>>> On Thu, Mar 19, 2015 at 04:58:33PM -0400, Jeff Moyer wrote:
>>>> Do you really want to do memory allocation in the exit path? That
>>>> sounds like a bad idea to me. (Of course, now you're going to point out
>>>> all the places that currently happens, right? ;-)
>>>
>>> I think we just need a counter there - let everyone count down as they
>>> exit and the last one trigger the completion, no?
>>
>> Yeah that's a good point, that'd be cleaner too. I'll change it and test
>> that.
>
> Here's a cleaner variant that pairs the completion even with an atomic
> count. Works for me as well.

I like this version. I ran it though the libaio test harness and
xfstests aio tests and it passed.

Thanks, Jens!

Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
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