gem_wsim: Late balancing decision mode

An approximation of in kernel balancing where balancing
decision is postponed to just before submitting the batch
for execution.

This is implemented by waiting on data dependencies in
userspace before submitting each batch.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

1 files changed, 44 insertions, 4 deletions

diff --git a/benchmarks/gem_wsim.c b/benchmarks/gem_wsim.c
index 2ce1aebcc..b6e10ae16 100644
--- a/benchmarks/gem_wsim.c
+++ b/benchmarks/gem_wsim.c
@@ -207,6 +207,7 @@ static int fd;
 #define SYNCEDCLIENTS	(1<<6)
 #define HEARTBEAT	(1<<7)
 #define GLOBAL_BALANCE	(1<<8)
+#define DEPSYNC		(1<<9)
 
 #define SEQNO_IDX(engine) ((engine) * 16)
 #define SEQNO_OFFSET(engine) (SEQNO_IDX(engine) * sizeof(uint32_t))
@@ -1553,11 +1554,38 @@ do_eb(struct workload *wrk, struct w_step *w, enum intel_engine_id engine,
 	}
 }
 
+static bool sync_deps(struct workload *wrk, struct w_step *w)
+{
+	bool synced = false;
+	unsigned int i;
+
+	for (i = 0; i < w->data_deps.nr; i++) {
+		int dep_idx;
+
+		igt_assert(w->data_deps.list[i] <= 0);
+
+		if (!w->data_deps.list[i])
+			continue;
+
+		dep_idx = w->idx + w->data_deps.list[i];
+
+		igt_assert(dep_idx >= 0 && dep_idx < w->idx);
+		igt_assert(wrk->steps[dep_idx].type == BATCH);
+
+		gem_sync(fd, wrk->steps[dep_idx].obj[0].handle);
+
+		synced = true;
+	}
+
+	return synced;
+}
+
 static void *run_workload(void *data)
 {
 	struct workload *wrk = (struct workload *)data;
 	struct timespec t_start, t_end;
 	struct w_step *w;
+	bool last_sync = false;
 	int throttle = -1;
 	int qd_throttle = -1;
 	int count;
@@ -1633,6 +1661,14 @@ static void *run_workload(void *data)
 
 			igt_assert(w->type == BATCH);
 
+			if ((wrk->flags & DEPSYNC) && engine == VCS)
+				last_sync = sync_deps(wrk, w);
+
+			if (last_sync && (wrk->flags & HEARTBEAT))
+				init_status_page(wrk, 0);
+
+			last_sync = false;
+
 			wrk->nr_bb[engine]++;
 			if (engine == VCS && wrk->balancer) {
 				engine = wrk->balancer->balance(wrk->balancer,
@@ -1658,8 +1694,7 @@ static void *run_workload(void *data)
 
 			if (w->sync) {
 				gem_sync(fd, w->obj[0].handle);
-				if (wrk->flags & HEARTBEAT)
-					init_status_page(wrk, 0);
+				last_sync = true;
 			}
 
 			if (qd_throttle > 0) {
@@ -1670,6 +1705,7 @@ static void *run_workload(void *data)
 								 s, rq_link);
 
 					gem_sync(fd, s->obj[0].handle);
+					last_sync = true;
 
 					s->request = -1;
 					igt_list_del(&s->rq_link);
@@ -1822,7 +1858,8 @@ static void print_help(void)
 "  -S              Synchronize the sequence of random batch durations between\n"
 "                  clients.\n"
 "  -G              Global load balancing - a single load balancer will be shared\n"
-"                  between all clients and there will be a single seqno domain."
+"                  between all clients and there will be a single seqno domain.\n"
+"  -d              Sync between data dependencies in userspace."
 	);
 }
 
@@ -1957,7 +1994,7 @@ int main(int argc, char **argv)
 
 	init_clocks();
 
-	while ((c = getopt(argc, argv, "hqv2RSHxGc:n:r:w:W:a:t:b:p:")) != -1) {
+	while ((c = getopt(argc, argv, "hqv2RSHxGdc:n:r:w:W:a:t:b:p:")) != -1) {
 		switch (c) {
 		case 'W':
 			if (master_workload >= 0) {
@@ -2019,6 +2056,9 @@ int main(int argc, char **argv)
 		case 'G':
 			flags |= GLOBAL_BALANCE;
 			break;
+		case 'd':
+			flags |= DEPSYNC;
+			break;
 		case 'b':
 			i = find_balancer_by_name(optarg);
 			if (i < 0) {