From c130456cefd4cf9531f12f3e9b23805d34706ac0 Mon Sep 17 00:00:00 2001
From: Changbin Du <changbin.du@intel.com>
Date: Wed, 29 Nov 2017 15:40:07 +0800
Subject: [PATCH] drm/i915/gvt: Kick scheduler when new workload queued
Git-commit: c130456cefd4cf9531f12f3e9b23805d34706ac0
Patch-mainline: v4.16-rc1
References: FATE#322643 bsc#1055900

The current schedule policy rely on a 1ms timer to execute workload. This
can introduce maximum 1ms unnecessary latency. This is especially bad for
small media workloads.

And I don't think we need this timer for QoS, but the change is not simply
remove the code. So I made a new API intel_gvt_kick_schedule() for future
change.

Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/gvt/sched_policy.c |    5 +++++
 drivers/gpu/drm/i915/gvt/sched_policy.h |    2 ++
 drivers/gpu/drm/i915/gvt/scheduler.c    |    1 +
 3 files changed, 8 insertions(+)

--- a/drivers/gpu/drm/i915/gvt/sched_policy.c
+++ b/drivers/gpu/drm/i915/gvt/sched_policy.c
@@ -372,6 +372,11 @@ void intel_vgpu_start_schedule(struct in
 	vgpu->gvt->scheduler.sched_ops->start_schedule(vgpu);
 }
 
+void intel_gvt_kick_schedule(struct intel_gvt *gvt)
+{
+	intel_gvt_request_service(gvt, INTEL_GVT_REQUEST_EVENT_SCHED);
+}
+
 void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
 {
 	struct intel_gvt_workload_scheduler *scheduler =
--- a/drivers/gpu/drm/i915/gvt/sched_policy.h
+++ b/drivers/gpu/drm/i915/gvt/sched_policy.h
@@ -57,4 +57,6 @@ void intel_vgpu_start_schedule(struct in
 
 void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu);
 
+void intel_gvt_kick_schedule(struct intel_gvt *gvt);
+
 #endif
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -1340,5 +1340,6 @@ void intel_vgpu_queue_workload(struct in
 {
 	list_add_tail(&workload->list,
 		workload_q_head(workload->vgpu, workload->ring_id));
+	intel_gvt_kick_schedule(workload->vgpu->gvt);
 	wake_up(&workload->vgpu->gvt->scheduler.waitq[workload->ring_id]);
 }