From d99f7b079c2a49b2278fe80192fbca083db87d18 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 8 Oct 2019 11:56:55 +0100
Subject: [PATCH] drm/i915/gt: Flush submission tasklet before waiting/retiring
Git-commit: d99f7b079c2a49b2278fe80192fbca083db87d18
Patch-mainline: v5.5-rc1
References: bsc#1174737
A common bane of ours is arbitrary delays in ksoftirqd processing our
submission tasklet. Give the submission tasklet a kick before we wait to
avoid those delays eating into a tight timeout.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008105655.13256-1-chris@chris-wilson.co.uk
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/gt/intel_engine.h | 3 +-
drivers/gpu/drm/i915/gt/intel_engine_cs.c | 33 ++++++++++++++++++------------
2 files changed, 22 insertions(+), 14 deletions(-)
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -430,8 +430,9 @@ static inline void __intel_engine_reset(
engine->serial++; /* contexts lost */
}
-bool intel_engine_is_idle(struct intel_engine_cs *engine);
bool intel_engines_are_idle(struct intel_gt *gt);
+bool intel_engine_is_idle(struct intel_engine_cs *engine);
+void intel_engine_flush_submission(struct intel_engine_cs *engine);
void intel_engines_reset_default_submission(struct intel_gt *gt);
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -1037,6 +1037,25 @@ static bool ring_is_idle(struct intel_en
return idle;
}
+void intel_engine_flush_submission(struct intel_engine_cs *engine)
+{
+ struct tasklet_struct *t = &engine->execlists.tasklet;
+
+ if (__tasklet_is_scheduled(t)) {
+ local_bh_disable();
+ if (tasklet_trylock(t)) {
+ /* Must wait for any GPU reset in progress. */
+ if (__tasklet_is_enabled(t))
+ t->func(t->data);
+ tasklet_unlock(t);
+ }
+ local_bh_enable();
+ }
+
+ /* Otherwise flush the tasklet if it was running on another cpu */
+ tasklet_unlock_wait(t);
+}
+
/**
* intel_engine_is_idle() - Report if the engine has finished process all work
* @engine: the intel_engine_cs
@@ -1055,21 +1074,9 @@ bool intel_engine_is_idle(struct intel_e
/* Waiting to drain ELSP? */
if (execlists_active(&engine->execlists)) {
- struct tasklet_struct *t = &engine->execlists.tasklet;
-
synchronize_hardirq(engine->i915->drm.pdev->irq);
- local_bh_disable();
- if (tasklet_trylock(t)) {
- /* Must wait for any GPU reset in progress. */
- if (__tasklet_is_enabled(t))
- t->func(t->data);
- tasklet_unlock(t);
- }
- local_bh_enable();
-
- /* Otherwise flush the tasklet if it was on another cpu */
- tasklet_unlock_wait(t);
+ intel_engine_flush_submission(engine);
if (execlists_active(&engine->execlists))
return false;