Re: [PATCH 1/2] drm/i915/execlists: Pull tasklet interrupt-bh local to direct submission

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 24/03/2020 12:07, Chris Wilson wrote:
We dropped calling process_csb prior to handling direct submission in
order to avoid the nesting of spinlocks and lift process_csb() and the
majority of the tasklet out of irq-off. However, we do want to avoid
ksoftirqd latency in the fast path, so try and pull the interrupt-bh
local to direct submission if we can acquire the tasklet's lock.

Oh and important question - who benefits and how much?

Regards,

Tvrtko

Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
---
  drivers/gpu/drm/i915/gt/intel_lrc.c | 6 ++++++
  1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 210f60e14ef4..82dee2141b46 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -2891,6 +2891,12 @@ static void __submit_queue_imm(struct intel_engine_cs *engine)
  	if (reset_in_progress(execlists))
  		return; /* defer until we restart the engine following reset */
+ /* Hopefully we clear execlists->pending[] to let us through */
+	if (execlists->pending[0] && tasklet_trylock(&execlists->tasklet)) {
+		process_csb(engine);
+		tasklet_unlock(&execlists->tasklet);
+	}
+
  	__execlists_submission_tasklet(engine);
  }
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx



[Index of Archives]     [AMD Graphics]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux