On 2014-06-24 20:42, Ming Lei wrote:
> On Tue, Jun 24, 2014 at 10:53 PM, Ming Lei <tom.leiming@gmail.com> wrote:
>>  From API view, it isn't good to run all hw queues synchronously
>> in one context, since it isn't correct for multi hw queue case.
>>
>> So this patch adds 'async' parameter to blk_mq_start_hw_queue(),
>> and make blk_mq_start_hw_queues() to run hw queues asynchronously
>> at default.
>
> BTW, without the change, it is easy to trigger the WARN_ON() in
> __blk_mq_run_hw_queue().

Why not just have it call blk_mq_run_hw_queue()? Pass in async == false, 
but let the cpumask logic sort out if we need to force an async run.

-- 
Jens Axboe