Use a lockless list structure for destroyed contexts to avoid hammering
on global submission spin lock.
Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_context.c | 2 -
drivers/gpu/drm/i915/gt/intel_context_types.h | 3 +-
drivers/gpu/drm/i915/gt/uc/intel_guc.h | 3 +-
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 44 +++++--------------
4 files changed, 16 insertions(+), 36 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 5d0ec7c49b6a..4aacb4b0418d 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -403,8 +403,6 @@ intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
ce->guc_id.id = GUC_INVALID_LRC_ID;
INIT_LIST_HEAD(&ce->guc_id.link);
- INIT_LIST_HEAD(&ce->destroyed_link);
-
INIT_LIST_HEAD(&ce->parallel.child_list);
/*
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 30cd81ad8911..4532d43ec9c0 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -9,6 +9,7 @@
#include <linux/average.h>
#include <linux/kref.h>
#include <linux/list.h>
+#include <linux/llist.h>
#include <linux/mutex.h>
#include <linux/types.h>
@@ -224,7 +225,7 @@ struct intel_context {
* list when context is pending to be destroyed (deregistered with the
* GuC), protected by guc->submission_state.lock
*/
- struct list_head destroyed_link;
+ struct llist_node destroyed_link;
/** @parallel: sub-structure for parallel submission members */
struct {
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
index f9240d4baa69..705085058411 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
@@ -8,6 +8,7 @@
#include <linux/xarray.h>
#include <linux/delay.h>
+#include <linux/llist.h>
#include "intel_uncore.h"
#include "intel_guc_fw.h"
@@ -112,7 +113,7 @@ struct intel_guc {
* @destroyed_contexts: list of contexts waiting to be destroyed
* (deregistered with the GuC)
*/
- struct list_head destroyed_contexts;
+ struct llist_head destroyed_contexts;
/**
* @destroyed_worker: worker to deregister contexts, need as we
* need to take a GT PM reference and can't from destroy
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 0a03a30e4c6d..6f7643edc139 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -1771,7 +1771,7 @@ int intel_guc_submission_init(struct intel_guc *guc)
spin_lock_init(&guc->submission_state.lock);
INIT_LIST_HEAD(&guc->submission_state.guc_id_list);
ida_init(&guc->submission_state.guc_ids);
- INIT_LIST_HEAD(&guc->submission_state.destroyed_contexts);
+ init_llist_head(&guc->submission_state.destroyed_contexts);
INIT_WORK(&guc->submission_state.destroyed_worker,
destroyed_worker_func);
@@ -2696,26 +2696,18 @@ static void __guc_context_destroy(struct intel_context *ce)
}
}
+#define take_destroyed_contexts(guc) \
+ llist_del_all(&guc->submission_state.destroyed_contexts)
+
static void guc_flush_destroyed_contexts(struct intel_guc *guc)
{
- struct intel_context *ce;
- unsigned long flags;
+ struct intel_context *ce, *cn;
GEM_BUG_ON(!submission_disabled(guc) &&
guc_submission_initialized(guc));
- while (!list_empty(&guc->submission_state.destroyed_contexts)) {
- spin_lock_irqsave(&guc->submission_state.lock, flags);
- ce = list_first_entry_or_null(&guc->submission_state.destroyed_contexts,
- struct intel_context,
- destroyed_link);
- if (ce)
- list_del_init(&ce->destroyed_link);
- spin_unlock_irqrestore(&guc->submission_state.lock, flags);
-
- if (!ce)
- break;
-
+ llist_for_each_entry_safe(ce, cn, take_destroyed_contexts(guc),
+ destroyed_link) {
release_guc_id(guc, ce);
__guc_context_destroy(ce);
}
@@ -2723,23 +2715,11 @@ static void guc_flush_destroyed_contexts(struct intel_guc *guc)
static void deregister_destroyed_contexts(struct intel_guc *guc)
{
- struct intel_context *ce;
- unsigned long flags;
-
- while (!list_empty(&guc->submission_state.destroyed_contexts)) {
- spin_lock_irqsave(&guc->submission_state.lock, flags);
- ce = list_first_entry_or_null(&guc->submission_state.destroyed_contexts,
- struct intel_context,
- destroyed_link);
- if (ce)
- list_del_init(&ce->destroyed_link);
- spin_unlock_irqrestore(&guc->submission_state.lock, flags);
-
- if (!ce)
- break;
+ struct intel_context *ce, *cn;
+ llist_for_each_entry_safe(ce, cn, take_destroyed_contexts(guc),
+ destroyed_link)
guc_lrc_desc_unpin(ce);
- }
}
static void destroyed_worker_func(struct work_struct *w)
@@ -2771,8 +2751,8 @@ static void guc_context_destroy(struct kref *kref)
if (likely(!destroy)) {
if (!list_empty(&ce->guc_id.link))
list_del_init(&ce->guc_id.link);
- list_add_tail(&ce->destroyed_link,
- &guc->submission_state.destroyed_contexts);
+ llist_add(&ce->destroyed_link,
+ &guc->submission_state.destroyed_contexts);
} else {
__release_guc_id(guc, ce);
}
--
2.34.1
