[PATCH 2/2] drm/i915/gvt: Update time slice more frequently
Zhipeng Gong
zhipeng.gong at intel.com
Fri Mar 30 04:54:11 UTC 2018
When there is only one vGPU in GVT-g and it submits workloads
continuously, it will not be scheduled out, vgpu_update_timeslice
is not called and its sched_in_time is not updated.
Once this vGPU pauses to submit workload due to heavy host workload,
it get scheduled out and vgpu_update_timeslice is called, its left_ts
will be subtract by a big value from sched_out_time - sched_in_time.
When this vGPU is going to submit workload again, it will not be
scheduled in until its left_ts is reset, it could introduce several
hunderand milliseconds latency.
This patch updates time slice in every ms to update sched_in_time
timely.
Signed-off-by: Zhipeng Gong <zhipeng.gong at intel.com>
---
drivers/gpu/drm/i915/gvt/sched_policy.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/i915/gvt/sched_policy.c b/drivers/gpu/drm/i915/gvt/sched_policy.c
index f0ac281..7eccc10 100644
--- a/drivers/gpu/drm/i915/gvt/sched_policy.c
+++ b/drivers/gpu/drm/i915/gvt/sched_policy.c
@@ -53,7 +53,6 @@ struct vgpu_sched_data {
bool active;
ktime_t sched_in_time;
- ktime_t sched_out_time;
ktime_t sched_time;
ktime_t left_ts;
ktime_t allocated_ts;
@@ -68,15 +67,19 @@ struct gvt_sched_data {
struct list_head lru_runq_head;
};
-static void vgpu_update_timeslice(struct intel_vgpu *pre_vgpu)
+static void vgpu_update_timeslice(struct intel_vgpu *vgpu, ktime_t cur_time)
{
ktime_t delta_ts;
- struct vgpu_sched_data *vgpu_data = pre_vgpu->sched_data;
+ struct vgpu_sched_data *vgpu_data;
- delta_ts = vgpu_data->sched_out_time - vgpu_data->sched_in_time;
+ if (vgpu == NULL || vgpu == vgpu->gvt->idle_vgpu)
+ return;
- vgpu_data->sched_time += delta_ts;
- vgpu_data->left_ts -= delta_ts;
+ vgpu_data = vgpu->sched_data;
+ delta_ts = ktime_sub(cur_time, vgpu_data->sched_in_time);
+ vgpu_data->sched_time = ktime_add(vgpu_data->sched_time, delta_ts);
+ vgpu_data->left_ts = ktime_sub(vgpu_data->left_ts, delta_ts);
+ vgpu_data->sched_in_time = cur_time;
}
#define GVT_TS_BALANCE_PERIOD_MS 100
@@ -150,11 +153,7 @@ static void try_to_schedule_next_vgpu(struct intel_gvt *gvt)
}
cur_time = ktime_get();
- if (scheduler->current_vgpu) {
- vgpu_data = scheduler->current_vgpu->sched_data;
- vgpu_data->sched_out_time = cur_time;
- vgpu_update_timeslice(scheduler->current_vgpu);
- }
+ vgpu_update_timeslice(scheduler->current_vgpu, cur_time);
vgpu_data = scheduler->next_vgpu->sched_data;
vgpu_data->sched_in_time = cur_time;
@@ -227,13 +226,13 @@ void intel_gvt_schedule(struct intel_gvt *gvt)
{
struct gvt_sched_data *sched_data = gvt->scheduler.sched_data;
static ktime_t check_time;
+ ktime_t cur_time;
mutex_lock(&gvt->lock);
+ cur_time = ktime_get();
if (test_and_clear_bit(INTEL_GVT_REQUEST_SCHED,
(void *)&gvt->service_request)) {
- ktime_t cur_time = ktime_get();
-
if (ktime_sub(cur_time, check_time) >=
GVT_TS_BALANCE_PERIOD_MS * NSEC_PER_MSEC) {
check_time = cur_time;
@@ -242,6 +241,7 @@ void intel_gvt_schedule(struct intel_gvt *gvt)
}
clear_bit(INTEL_GVT_REQUEST_EVENT_SCHED, (void *)&gvt->service_request);
+ vgpu_update_timeslice(gvt->scheduler.current_vgpu, cur_time);
tbs_sched_func(sched_data);
mutex_unlock(&gvt->lock);
--
2.7.4
More information about the intel-gvt-dev
mailing list