Re: [PATCHv2 04/11] writeback: do not lose wake-ups in the forkerthread - 2

From: Christoph Hellwig
Date: Wed Jul 21 2010 - 07:57:31 EST


On Wed, Jul 21, 2010 at 12:31:39PM +0300, Artem Bityutskiy wrote:
> From: Artem Bityutskiy <Artem.Bityutskiy@xxxxxxxxx>
>
> Currently, if someone submits jobs for the default bdi, we can lose wake-up
> events. E.g., this can happen if 'bdi_queue_work()' is called when
> 'bdi_forker_thread()' is executing code after 'wb_do_writeback(me, 0)', but
> before 'set_current_state(TASK_INTERRUPTIBLE)'.
>
> This situation is unlikely, and the result is not very severe - we'll just
> delay the execution of the work, but this is still not very nice.
>
> This patch fixes the issue by checking whether the default bdi has works before
> the forker thread goes sleep.

Looks good,


Reviewed-by: Christoph Hellwig <hch@xxxxxx>

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