On Thu, Aug 15, 2019 at 8:46 PM Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > Quoting Daniel Vetter (2019-08-14 18:20:53) > > On Sun, Aug 11, 2019 at 10:15:23AM +0100, Chris Wilson wrote: > > > Now that dma_fence_signal always takes the spinlock to flush the > > > cb_list, simply take the spinlock and call dma_fence_signal_locked() to > > > avoid code repetition. > > > > > > Suggested-by: Christian König <christian.koenig@xxxxxxx> > > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > Cc: Christian König <christian.koenig@xxxxxxx> > > > > Hm, I think this largely defeats the point of having the lockless signal > > enabling trickery in dma_fence. Maybe that part isn't needed by anyone, > > but feels like a thing that needs a notch more thought. And if we need it, > > maybe a bit more cleanup. > > You mean dma_fence_enable_sw_signaling(). The only user appears to be to > flush fences, which is actually the intent of always notifying the signal > cb. By always doing the callbacks, we can avoid installing the interrupt > and completely saturating CPUs with irqs, instead doing a batch in a > leisurely timer callback if not flushed naturally. Yeah I'm not against ditching this, but can't we ditch a lot more if we just always take the spinlock in those paths now anyways? Kinda not worth having the complexity anymore. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
