From 7651a4452ddf8ace48defd473ead6effe35059c7 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 1 Oct 2018 13:32:03 +0100 Subject: drm/i915: Reserve some priority bits for internal use In the next few patches, we will want to give a small priority boost to some requests/queues but not so much that we perturb the user controlled order. As such we will shift the user priority bits higher leaving ourselves a few low priority bits for our internal bumping. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20181001123204.23982-3-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_scheduler.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/gpu/drm/i915/i915_scheduler.h') diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h index 70a42220358d..89d456312557 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.h +++ b/drivers/gpu/drm/i915/i915_scheduler.h @@ -19,6 +19,12 @@ enum { I915_PRIORITY_INVALID = INT_MIN }; +#define I915_USER_PRIORITY_SHIFT 0 +#define I915_USER_PRIORITY(x) ((x) << I915_USER_PRIORITY_SHIFT) + +#define I915_PRIORITY_COUNT BIT(I915_USER_PRIORITY_SHIFT) +#define I915_PRIORITY_MASK (I915_PRIORITY_COUNT - 1) + struct i915_sched_attr { /** * @priority: execution and service priority -- cgit v1.2.3 From b16c765122f987056e1dc9ef6c214571bb5bd694 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 1 Oct 2018 15:47:53 +0100 Subject: drm/i915: Priority boost for new clients Taken from an idea used for FQ_CODEL, we give the first request of a new request flows a small priority boost. These flows are likely to correspond with short, interactive tasks and so be more latency sensitive than the longer free running queues. As soon as the client has more than one request in the queue, further requests are not boosted and it settles down into ordinary steady state behaviour. Such small kicks dramatically help combat the starvation issue, by allowing each client the opportunity to run even when the system is under heavy throughput load (within the constraints of the user selected priority). v2: Mark the preempted request as the start of a new flow, to prevent a single client being continually gazumped by its peers. Testcase: igt/benchmarks/rrul Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Joonas Lahtinen Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20181001144755.7978-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_scheduler.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/i915/i915_scheduler.h') diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h index 89d456312557..53dc7dbf88b9 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.h +++ b/drivers/gpu/drm/i915/i915_scheduler.h @@ -19,12 +19,14 @@ enum { I915_PRIORITY_INVALID = INT_MIN }; -#define I915_USER_PRIORITY_SHIFT 0 +#define I915_USER_PRIORITY_SHIFT 1 #define I915_USER_PRIORITY(x) ((x) << I915_USER_PRIORITY_SHIFT) #define I915_PRIORITY_COUNT BIT(I915_USER_PRIORITY_SHIFT) #define I915_PRIORITY_MASK (I915_PRIORITY_COUNT - 1) +#define I915_PRIORITY_NEWCLIENT ((u8)BIT(0)) + struct i915_sched_attr { /** * @priority: execution and service priority -- cgit v1.2.3 From e2f3496e93be3238de2e2e6bfc83b3a83c084ce5 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 1 Oct 2018 15:47:54 +0100 Subject: drm/i915: Pull scheduling under standalone lock Currently, the backend scheduling code abuses struct_mutex into order to have a global lock to manipulate a temporary list (without widespread allocation) and to protect against list modifications. This is an extraneous coupling to struct_mutex and further can not extend beyond the local device. Pull all the code that needs to be under the one true lock into i915_scheduler.c, and make it so. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20181001144755.7978-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_scheduler.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'drivers/gpu/drm/i915/i915_scheduler.h') diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h index 53dc7dbf88b9..68d84a45ad7f 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.h +++ b/drivers/gpu/drm/i915/i915_scheduler.h @@ -8,9 +8,14 @@ #define _I915_SCHEDULER_H_ #include +#include #include +struct drm_i915_private; +struct i915_request; +struct intel_engine_cs; + enum { I915_PRIORITY_MIN = I915_CONTEXT_MIN_USER_PRIORITY - 1, I915_PRIORITY_NORMAL = I915_CONTEXT_DEFAULT_PRIORITY, @@ -77,4 +82,24 @@ struct i915_dependency { #define I915_DEPENDENCY_ALLOC BIT(0) }; +void i915_sched_node_init(struct i915_sched_node *node); + +bool __i915_sched_node_add_dependency(struct i915_sched_node *node, + struct i915_sched_node *signal, + struct i915_dependency *dep, + unsigned long flags); + +int i915_sched_node_add_dependency(struct drm_i915_private *i915, + struct i915_sched_node *node, + struct i915_sched_node *signal); + +void i915_sched_node_fini(struct drm_i915_private *i915, + struct i915_sched_node *node); + +void i915_schedule(struct i915_request *request, + const struct i915_sched_attr *attr); + +struct list_head * +i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio); + #endif /* _I915_SCHEDULER_H_ */ -- cgit v1.2.3 From e9eaf82d97a2b05460ff5ef6a3e07446f7d049fe Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 1 Oct 2018 15:47:55 +0100 Subject: drm/i915: Priority boost for waiting clients Latency is in the eye of the beholder. In the case where a client stops and waits for the gpu, give that request chain a small priority boost (not so that it overtakes higher priority clients, to preserve the external ordering) so that ideally the wait completes earlier. v2: Tvrtko recommends to keep the boost-from-user-stall as small as possible and to allow new client flows to be preferred for interactivity over stalls. Testcase: igt/gem_sync/switch-default Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Joonas Lahtinen Cc: Dmitry Rogozhkin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20181001144755.7978-3-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_scheduler.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/i915/i915_scheduler.h') diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h index 68d84a45ad7f..dbe9cb7ecd82 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.h +++ b/drivers/gpu/drm/i915/i915_scheduler.h @@ -24,13 +24,14 @@ enum { I915_PRIORITY_INVALID = INT_MIN }; -#define I915_USER_PRIORITY_SHIFT 1 +#define I915_USER_PRIORITY_SHIFT 2 #define I915_USER_PRIORITY(x) ((x) << I915_USER_PRIORITY_SHIFT) #define I915_PRIORITY_COUNT BIT(I915_USER_PRIORITY_SHIFT) #define I915_PRIORITY_MASK (I915_PRIORITY_COUNT - 1) -#define I915_PRIORITY_NEWCLIENT ((u8)BIT(0)) +#define I915_PRIORITY_WAIT ((u8)BIT(0)) +#define I915_PRIORITY_NEWCLIENT ((u8)BIT(1)) struct i915_sched_attr { /** @@ -99,6 +100,8 @@ void i915_sched_node_fini(struct drm_i915_private *i915, void i915_schedule(struct i915_request *request, const struct i915_sched_attr *attr); +void i915_schedule_bump_priority(struct i915_request *rq, unsigned int bump); + struct list_head * i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio); -- cgit v1.2.3