From f100daec9c9a5bbf1a715323cb6102e99933fdb3 Mon Sep 17 00:00:00 2001
From: Ping Gao <ping.a.gao@intel.com>
Date: Wed, 24 May 2017 09:14:11 +0800
Subject: [PATCH] drm/i915/gvt: Trigger scheduling after context complete
Git-commit: f100daec9c9a5bbf1a715323cb6102e99933fdb3
Patch-mainline: v4.13-rc1
References: FATE#322643 bsc#1055900

The time based scheduler poll context busy status at every
micro-second during vGPU switch, it will make GPU idle for a while
when the context is very small and completed before the next
micro-second arrival. Trigger scheduling immediately after context
complete will eliminate GPU idle and improve performance.

Create two vGPU with same type, run Heaven simultaneously:
Before this patch:
 +---------+----------+----------+
 |         |  vGPU1   |   vGPU2  |
 +---------+----------+----------+
 |  Heaven |  357     |    354   |
 +-------------------------------+

After this patch:
 +---------+----------+----------+
 |         |  vGPU1   |   vGPU2  |
 +---------+----------+----------+
 |  Heaven |  397     |    398   |
 +-------------------------------+

V2: Let need_reschedule protect by gvt-lock.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Signed-off-by: Weinan Li <weinan.z.li@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/gvt/scheduler.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -452,6 +452,10 @@ static void complete_current_workload(st
 
 	atomic_dec(&vgpu->running_workload_num);
 	wake_up(&scheduler->workload_complete_wq);
+
+	if (gvt->scheduler.need_reschedule)
+		intel_gvt_request_service(gvt, INTEL_GVT_REQUEST_EVENT_SCHED);
+
 	mutex_unlock(&gvt->lock);
 }