Lift moving the timeline to/from the active_list on enter/exit in order
to shorten the active tracking span in comparison to the existing
pin/unpin.
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.a...@intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_pm.c | 1 -
drivers/gpu/drm/i915/gt/intel_context.c | 2 +
drivers/gpu/drm/i915/gt/intel_engine_pm.c | 2 +
drivers/gpu/drm/i915/gt/intel_lrc.c | 4 +
drivers/gpu/drm/i915/gt/intel_timeline.c | 98 +++++++------------
drivers/gpu/drm/i915/gt/intel_timeline.h | 3 +-
.../gpu/drm/i915/gt/intel_timeline_types.h | 18 ++++
drivers/gpu/drm/i915/gt/selftest_timeline.c | 2 -
8 files changed, 64 insertions(+), 66 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pm.c
b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
index 17e3618241c5..92e53c25424c 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
@@ -37,7 +37,6 @@ static void i915_gem_park(struct drm_i915_private *i915)
for_each_engine(engine, i915, id)
call_idle_barriers(engine); /* cleanup after wedging */
- intel_timelines_park(i915);
i915_vma_parked(i915);
i915_globals_park();
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c
b/drivers/gpu/drm/i915/gt/intel_context.c
index 77833f1558a9..9114953bf920 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -280,10 +280,12 @@ int __init i915_global_context_init(void)
void intel_context_enter_engine(struct intel_context *ce)
{
intel_engine_pm_get(ce->engine);
+ intel_timeline_enter(ce->timeline);
}
void intel_context_exit_engine(struct intel_context *ce)
{
+ intel_timeline_exit(ce->timeline);
intel_engine_pm_put(ce->engine);
}
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
index 49ad02c3720f..f3f0109f9e22 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
@@ -66,6 +66,8 @@ static bool switch_to_kernel_context(struct intel_engine_cs
*engine)
/* Context switch failed, hope for the best! Maybe reset? */
return true;
+ intel_timeline_enter(rq->timeline);
+
/* Check again on the next retirement. */
engine->wakeref_serial = engine->serial + 1;
i915_request_add_active_barriers(rq);
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c
b/drivers/gpu/drm/i915/gt/intel_lrc.c
index a5d9b902d6e3..b4c2662dbc75 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -3306,6 +3306,8 @@ static void virtual_context_enter(struct intel_context
*ce)
for (n = 0; n < ve->num_siblings; n++)
intel_engine_pm_get(ve->siblings[n]);
+
+ intel_timeline_enter(ce->timeline);
}
static void virtual_context_exit(struct intel_context *ce)
@@ -3313,6 +3315,8 @@ static void virtual_context_exit(struct intel_context *ce)
struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
unsigned int n;
+ intel_timeline_exit(ce->timeline);
+
for (n = 0; n < ve->num_siblings; n++)
intel_engine_pm_put(ve->siblings[n]);
}
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c
b/drivers/gpu/drm/i915/gt/intel_timeline.c
index 6daa9eb59e19..4af0b9801d91 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline.c
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.c
@@ -278,64 +278,11 @@ void intel_timelines_init(struct drm_i915_private *i915)
timelines_init(&i915->gt);
}
-static void timeline_add_to_active(struct intel_timeline *tl)
-{
- struct intel_gt_timelines *gt = &tl->gt->timelines;
-
- mutex_lock(>->mutex);
- list_add(&tl->link, >->active_list);
- mutex_unlock(>->mutex);
-}
-
-static void timeline_remove_from_active(struct intel_timeline *tl)
-{
- struct intel_gt_timelines *gt = &tl->gt->timelines;
-
- mutex_lock(>->mutex);
- list_del(&tl->link);
- mutex_unlock(>->mutex);
-}
-
-static void timelines_park(struct intel_gt *gt)
-{
- struct intel_gt_timelines *timelines = >->timelines;
- struct intel_timeline *timeline;
-
- mutex_lock(&timelines->mutex);
- list_for_each_entry(timeline, &timelines->active_list, link) {
- /*
- * All known fences are completed so we can scrap
- * the current sync point tracking and start afresh,
- * any attempt to wait upon a previous sync point
- * will be skipped as the fence was signaled.
- */
- i915_syncmap_free(&timeline->sync);
- }
- mutex_unlock(&timelines->mutex);
-}
-
-/**
- * intel_timelines_park - called when the driver idles
- * @i915: the drm_i915_private device
- *
- * When the driver is completely idle, we know that all of our sync points
- * have been signaled and our tracking is then entirely redundant. Any request
- * to wait upon an older sync point will be completed instantly as we know
- * the fence is signaled and therefore we will not even look them up in the
- * sync point map.
- */
-void intel_timelines_park(struct drm_i915_private *i915)
-{
- timelines_park(&i915->gt);
-}
-
void intel_timeline_fini(struct intel_timeline *timeline)
{
GEM_BUG_ON(timeline->pin_count);
GEM_BUG_ON(!list_empty(&timeline->requests));
- i915_syncmap_free(&timeline->sync);
-
if (timeline->hwsp_cacheline)
cacheline_free(timeline->hwsp_cacheline);
else
@@ -370,6 +317,7 @@ int intel_timeline_pin(struct intel_timeline *tl)
if (tl->pin_count++)
return 0;
GEM_BUG_ON(!tl->pin_count);
+ GEM_BUG_ON(tl->active_count);
err = i915_vma_pin(tl->hwsp_ggtt, 0, 0, PIN_GLOBAL | PIN_HIGH);
if (err)
@@ -380,7 +328,6 @@ int intel_timeline_pin(struct intel_timeline *tl)
offset_in_page(tl->hwsp_offset);
cacheline_acquire(tl->hwsp_cacheline);
- timeline_add_to_active(tl);
return 0;
@@ -389,6 +336,40 @@ int intel_timeline_pin(struct intel_timeline *tl)
return err;
}
+void intel_timeline_enter(struct intel_timeline *tl)
+{
+ struct intel_gt_timelines *timelines = &tl->gt->timelines;
+
+ GEM_BUG_ON(!tl->pin_count);
+ if (tl->active_count++)
+ return;
+ GEM_BUG_ON(!tl->active_count); /* overflow? */
+
+ mutex_lock(&timelines->mutex);
+ list_add(&tl->link, &timelines->active_list);
+ mutex_unlock(&timelines->mutex);
+}
+
+void intel_timeline_exit(struct intel_timeline *tl)
+{
+ struct intel_gt_timelines *timelines = &tl->gt->timelines;
+
+ GEM_BUG_ON(!tl->active_count);
+ if (--tl->active_count)
+ return;
+
+ mutex_lock(&timelines->mutex);
+ list_del(&tl->link);
+ mutex_unlock(&timelines->mutex);
+
+ /*
+ * Since this timeline is idle, all bariers upon which we were waiting
+ * must also be complete and so we can discard the last used barriers
+ * without loss of information.
+ */
+ i915_syncmap_free(&tl->sync);
+}
+
static u32 timeline_advance(struct intel_timeline *tl)
{
GEM_BUG_ON(!tl->pin_count);
@@ -546,16 +527,9 @@ void intel_timeline_unpin(struct intel_timeline *tl)
if (--tl->pin_count)
return;
- timeline_remove_from_active(tl);
+ GEM_BUG_ON(tl->active_count);
cacheline_release(tl->hwsp_cacheline);
- /*
- * Since this timeline is idle, all bariers upon which we were waiting
- * must also be complete and so we can discard the last used barriers
- * without loss of information.
- */
- i915_syncmap_free(&tl->sync);
-
__i915_vma_unpin(tl->hwsp_ggtt);
}
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.h
b/drivers/gpu/drm/i915/gt/intel_timeline.h
index e08cebf64833..f583af1ba18d 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline.h
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.h
@@ -77,9 +77,11 @@ static inline bool intel_timeline_sync_is_later(struct
intel_timeline *tl,
}
int intel_timeline_pin(struct intel_timeline *tl);
+void intel_timeline_enter(struct intel_timeline *tl);
int intel_timeline_get_seqno(struct intel_timeline *tl,
struct i915_request *rq,
u32 *seqno);
+void intel_timeline_exit(struct intel_timeline *tl);
void intel_timeline_unpin(struct intel_timeline *tl);
int intel_timeline_read_hwsp(struct i915_request *from,
@@ -87,7 +89,6 @@ int intel_timeline_read_hwsp(struct i915_request *from,
u32 *hwsp_offset);
void intel_timelines_init(struct drm_i915_private *i915);
-void intel_timelines_park(struct drm_i915_private *i915);
void intel_timelines_fini(struct drm_i915_private *i915);
#endif
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline_types.h
b/drivers/gpu/drm/i915/gt/intel_timeline_types.h
index 9a71aea7a338..b1a9f0c54bf0 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_timeline_types.h
@@ -25,7 +25,25 @@ struct intel_timeline {
struct mutex mutex; /* protects the flow of requests */
+ /*
+ * pin_count and active_count track essentially the same thing:
+ * How many requests are in flight or may be under construction.
+ *
+ * We need two distinct counters so that we can assign different
+ * lifetimes to the events for different use-cases. For example,
+ * we want to permanently keep the timeline pinned for the kernel
+ * context so that we can issue requests at any time without having
+ * to acquire space in the GGTT. However, we want to keep tracking
+ * the activity (to be able to detect when we become idle) along that
+ * permanently pinned timeline and so end up requiring two counters.
+ *
+ * Note that the active_count is protected by the intel_timeline.mutex,
+ * but the pin_count is protected by a combination of serialisation
+ * from the intel_context caller plus internal atomicity.
+ */
unsigned int pin_count;
+ unsigned int active_count;
+
const u32 *hwsp_seqno;
struct i915_vma *hwsp_ggtt;
u32 hwsp_offset;
diff --git a/drivers/gpu/drm/i915/gt/selftest_timeline.c
b/drivers/gpu/drm/i915/gt/selftest_timeline.c
index f0a840030382..d54113697745 100644
--- a/drivers/gpu/drm/i915/gt/selftest_timeline.c
+++ b/drivers/gpu/drm/i915/gt/selftest_timeline.c
@@ -816,8 +816,6 @@ static int live_hwsp_recycle(void *arg)
if (err)
goto out;
-
- intel_timelines_park(i915); /* Encourage recycling! */
} while (!__igt_timeout(end_time, NULL));
}
--
2.23.0.rc1
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