On ma, 2017-06-05 at 11:26 +0100, Chris Wilson wrote:
> Originally we would enable and disable the breadcrumb interrupt
> immediately on demand. This was slow enough to have a large impact
> (>30%) on tasks that hopped between engines. However, by using a shadow
> to keep the irq alive for an extra interrupt (see commit 67b807a89230
> ("drm/i915: Delay disabling the user interrupt for breadcrumbs")) and
> by recently reducing the cost in adding ourselves to the signal tree, we
> no longer need to spin-request during await_request to avoid delays in
> throughput tests. Without the earlier patches to stop the wakeup when
> signaling if the irq was already active, we saw no improvement in
> execbuf overhead (and corresponding contention in other clients) despite
> the removal of the spinner in a simple test like glxgears. This means
> that will be scenarios where now we spend longer enabling the interrupt^ there ? "now where we" ? > than we would have spent spinning, but these are not likely to have as > noticeable an impact as the high frequency test cases (where there > should not be any regression). > > Ulterior motive: generalising the engine->sync_to to handle different > types of semaphores and non-semaphores. > > Signed-off-by: Chris Wilson <[email protected]> > Cc: Joonas Lahtinen <[email protected]> > Cc: Tvrtko Ursulin <[email protected]> > Cc: Oscar Mateo <[email protected]> Does what is described, so code itself is: Reviewed-by: Joonas Lahtinen <[email protected]> Some Testcase:'s would be cool, without those it's bit handwavy. Maybe an Ack from Tvrtko. Regards, Joonas -- Joonas Lahtinen Open Source Technology Center Intel Corporation _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
