From: Zhipeng Gong <zhipeng.gong@intel.com>
Date: Wed, 4 Apr 2018 08:43:52 +0800
Subject: drm/i915/gvt: Use real time to do timer check
Git-commit: 292bb0d38a5714440b59ef910404408d5e9a8017
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
intel_gvt_schedule check timer through a counter and is supposed
to wake up to increase the counter every ms.
In a system with heavy workload, gvt_service_thread can not get
a chance to run right after wake up and will be delayed several
milliseconds. As a result, one hundred counter interval means
several hundred milliseconds in real time.
This patch use real time instead of counter to do timer check.
v2: remove static variable. (Zhenyu)
v3: correct expire_time update. (Zhenyu)
Signed-off-by: Zhipeng Gong <zhipeng.gong@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Min He <min.he@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/gvt/sched_policy.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/gvt/sched_policy.c
+++ b/drivers/gpu/drm/i915/gvt/sched_policy.c
@@ -66,6 +66,7 @@ struct gvt_sched_data {
struct hrtimer timer;
unsigned long period;
struct list_head lru_runq_head;
+ ktime_t expire_time;
};
static void vgpu_update_timeslice(struct intel_vgpu *pre_vgpu)
@@ -226,14 +227,18 @@ out:
void intel_gvt_schedule(struct intel_gvt *gvt)
{
struct gvt_sched_data *sched_data = gvt->scheduler.sched_data;
- static uint64_t timer_check;
mutex_lock(&gvt->lock);
if (test_and_clear_bit(INTEL_GVT_REQUEST_SCHED,
(void *)&gvt->service_request)) {
- if (!(timer_check++ % GVT_TS_BALANCE_PERIOD_MS))
+ ktime_t cur_time = ktime_get();
+
+ if (cur_time >= sched_data->expire_time) {
gvt_balance_timeslice(sched_data);
+ sched_data->expire_time = ktime_add_ms(
+ cur_time, GVT_TS_BALANCE_PERIOD_MS);
+ }
}
clear_bit(INTEL_GVT_REQUEST_EVENT_SCHED, (void *)&gvt->service_request);