Re: [PATCH, RFC] simplify writeback thread creation

[Jens Axboe <axboe@kernel.dk>]

On 08/07/10 17.23, Artem Bityutskiy wrote:
> On Thu, 2010-07-08 at 16:59 +0200, Jens Axboe wrote:
>>> How about not starting any thread at all at the bdi registration time,
>>> and start a bdi thread only when something for this bdi becomes dirty
>>> (__mark_inode_dirty()) or a bdi work is queued (bdi_queue_work())? If we
>>> do this, then the tasks can also die by the 5min timeout, and will be
>>> forked again when dirt/bdi works arrives?
>>>
>>> I guess it is a bit challenging to start a task in __mark_inode_dirty(),
>>> whis is supposed to be fast and non-sleeping, but we can just submit a
>>> work which will start the task.
>>
>> That work would have to reside on the stack, and __mark_inode_dirty()
>> block on the thread startup. We can't always do that.
> 
> We can have a pre-defined bdi->wb->task_start_work or something like
> that.

Yeah, that would work.

-- 
Jens Axboe