[Intel-gfx] [PATCH] drm/i915: Try harder to finish the idle-worker

[Chris Wilson]

Quoting Daniel Vetter (2017-09-04 09:35:49)
> On Fri, Sep 01, 2017 at 03:11:23PM +0100, Chris Wilson wrote:
> > If a worker requeues itself, it may switch to a different kworker pool,
> > which flush_work() considers as complete. To be strict, we then need to
> > keep flushing the work until it is no longer pending.
> > 
> > References: https://bugs.freedesktop.org/show_bug.cgi?id=102456
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> 
> Shouldn't this be a thing the workqueue subsystem exposes? Adding Tejun et
> al.

The semantics are so horrible that I wouldn't suggest that the core
should expose such a nasty trap. You have to be absolutely certain that
your work stops requeueing itself.
-Chris