[igt-dev] [PATCH i-g-t 17/17] gem_wsim: Infinite batch support

Tvrtko Ursulin tursulin at ursulin.net
Thu Oct 18 15:28:15 UTC 2018


From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

For simulating frame split workloads it is useful to express a batch which
ends at the same time as the parallel submission on the respective bonded
engine. For this we add support for infinite batch durations and the batch
terminate command ('T'). Syntax looks like this:

  1.RCS.*.0.0
  T.-1

First step starts an infinite batch, and second command terminates the
infinite batch with the usual relative workload step addressing.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 benchmarks/gem_wsim.c                  | 119 +++++++++++++++++++------
 benchmarks/wsim/README                 |   9 +-
 benchmarks/wsim/frame-split-60fps.wsim |   6 +-
 3 files changed, 102 insertions(+), 32 deletions(-)

diff --git a/benchmarks/gem_wsim.c b/benchmarks/gem_wsim.c
index b5ade7b33883..3669c1f7f1c9 100644
--- a/benchmarks/gem_wsim.c
+++ b/benchmarks/gem_wsim.c
@@ -85,6 +85,7 @@ enum w_type
 	ENGINE_MAP,
 	LOAD_BALANCE,
 	BOND,
+	TERMINATE,
 };
 
 struct deps
@@ -112,6 +113,7 @@ struct w_step
 	unsigned int context;
 	unsigned int engine;
 	struct duration duration;
+	bool unbound_duration;
 	struct deps data_deps;
 	struct deps fence_deps;
 	int emit_fence;
@@ -142,7 +144,7 @@ struct w_step
 
 	struct drm_i915_gem_execbuffer2 eb;
 	struct drm_i915_gem_exec_object2 *obj;
-	struct drm_i915_gem_relocation_entry reloc[4];
+	struct drm_i915_gem_relocation_entry reloc[5];
 	unsigned long bb_sz;
 	uint32_t bb_handle;
 	uint32_t *mapped_batch;
@@ -153,6 +155,7 @@ struct w_step
 	uint32_t *rt1_address;
 	uint32_t *latch_value;
 	uint32_t *latch_address;
+	uint32_t *recursive_bb_start;
 	unsigned int mapped_len;
 };
 
@@ -492,6 +495,10 @@ parse_workload(struct w_arg *arg, unsigned int flags, struct workload *app_w)
 
 				step.type = ENGINE_MAP;
 				goto add_step;
+			} else if (!strcmp(field, "T")) {
+				int_field(TERMINATE, target,
+					  tmp >= 0 || ((int)nr_steps + tmp) < 0,
+					  "Invalid terminate target at step %u!\n");
 			} else if (!strcmp(field, "X")) {
 				unsigned int nr = 0;
 				while ((field = strtok_r(fstart, ".", &fctx))) {
@@ -598,23 +605,28 @@ parse_workload(struct w_arg *arg, unsigned int flags, struct workload *app_w)
 
 			fstart = NULL;
 
-			tmpl = strtol(field, &sep, 10);
-			check_arg(tmpl <= 0 || tmpl == LONG_MIN ||
-				  tmpl == LONG_MAX,
-				  "Invalid duration at step %u!\n", nr_steps);
-			step.duration.min = tmpl;
-
-			if (sep && *sep == '-') {
-				tmpl = strtol(sep + 1, NULL, 10);
-				check_arg(tmpl <= 0 ||
-					  tmpl <= step.duration.min ||
-					  tmpl == LONG_MIN ||
+			if (field[0] == '*') {
+				step.unbound_duration = true;
+			} else {
+				tmpl = strtol(field, &sep, 10);
+				check_arg(tmpl <= 0 || tmpl == LONG_MIN ||
 					  tmpl == LONG_MAX,
-					  "Invalid duration range at step %u!\n",
+					  "Invalid duration at step %u!\n",
 					  nr_steps);
-				step.duration.max = tmpl;
-			} else {
-				step.duration.max = step.duration.min;
+				step.duration.min = tmpl;
+
+				if (sep && *sep == '-') {
+					tmpl = strtol(sep + 1, NULL, 10);
+					check_arg(tmpl <= 0 ||
+						tmpl <= step.duration.min ||
+						tmpl == LONG_MIN ||
+						tmpl == LONG_MAX,
+						"Invalid duration range at step %u!\n",
+						nr_steps);
+					step.duration.max = tmpl;
+				} else {
+					step.duration.max = step.duration.min;
+				}
 			}
 
 			valid++;
@@ -773,7 +785,7 @@ init_bb(struct w_step *w, unsigned int flags)
 	unsigned int i;
 	uint32_t *ptr;
 
-	if (!arb_period)
+	if (w->unbound_duration || !arb_period)
 		return;
 
 	gem_set_domain(fd, w->bb_handle,
@@ -793,6 +805,7 @@ terminate_bb(struct w_step *w, unsigned int flags)
 	const uint32_t bbe = 0xa << 23;
 	unsigned long mmap_start, mmap_len;
 	unsigned long batch_start = w->bb_sz;
+	unsigned int r = 0;
 	uint32_t *ptr, *cs;
 
 	igt_assert(((flags & RT) && (flags & SEQNO)) || !(flags & RT));
@@ -803,6 +816,9 @@ terminate_bb(struct w_step *w, unsigned int flags)
 	if (flags & RT)
 		batch_start -= 12 * sizeof(uint32_t);
 
+	if (w->unbound_duration)
+		batch_start -= 4 * sizeof(uint32_t); /* MI_ARB_CHK + MI_BATCH_BUFFER_START */
+
 	mmap_start = rounddown(batch_start, PAGE_SIZE);
 	mmap_len = w->bb_sz - mmap_start;
 
@@ -812,8 +828,19 @@ terminate_bb(struct w_step *w, unsigned int flags)
 	ptr = gem_mmap__wc(fd, w->bb_handle, mmap_start, mmap_len, PROT_WRITE);
 	cs = (uint32_t *)((char *)ptr + batch_start - mmap_start);
 
+	if (w->unbound_duration) {
+		w->reloc[r++].offset = batch_start + 2 * sizeof(uint32_t);
+		batch_start += 4 * sizeof(uint32_t);
+
+		*cs++ = w->preempt_us ? 0x5 << 23 /* MI_ARB_CHK; */ : MI_NOOP;
+		w->recursive_bb_start = cs;
+		*cs++ = MI_BATCH_BUFFER_START | 1 << 8 | 1;
+		*cs++ = 0;
+		*cs++ = 0;
+	}
+
 	if (flags & SEQNO) {
-		w->reloc[0].offset = batch_start + sizeof(uint32_t);
+		w->reloc[r++].offset = batch_start + sizeof(uint32_t);
 		batch_start += 4 * sizeof(uint32_t);
 
 		*cs++ = MI_STORE_DWORD_IMM;
@@ -825,7 +852,7 @@ terminate_bb(struct w_step *w, unsigned int flags)
 	}
 
 	if (flags & RT) {
-		w->reloc[1].offset = batch_start + sizeof(uint32_t);
+		w->reloc[r++].offset = batch_start + sizeof(uint32_t);
 		batch_start += 4 * sizeof(uint32_t);
 
 		*cs++ = MI_STORE_DWORD_IMM;
@@ -835,7 +862,7 @@ terminate_bb(struct w_step *w, unsigned int flags)
 		w->rt0_value = cs;
 		*cs++ = 0;
 
-		w->reloc[2].offset = batch_start + 2 * sizeof(uint32_t);
+		w->reloc[r++].offset = batch_start + 2 * sizeof(uint32_t);
 		batch_start += 4 * sizeof(uint32_t);
 
 		*cs++ = 0x24 << 23 | 2; /* MI_STORE_REG_MEM */
@@ -844,7 +871,7 @@ terminate_bb(struct w_step *w, unsigned int flags)
 		*cs++ = 0;
 		*cs++ = 0;
 
-		w->reloc[3].offset = batch_start + sizeof(uint32_t);
+		w->reloc[r++].offset = batch_start + sizeof(uint32_t);
 		batch_start += 4 * sizeof(uint32_t);
 
 		*cs++ = MI_STORE_DWORD_IMM;
@@ -979,19 +1006,28 @@ alloc_step_batch(struct workload *wrk, struct w_step *w, unsigned int flags)
 		}
 	}
 
-	w->bb_sz = get_bb_sz(w->duration.max);
-	w->bb_handle = w->obj[j].handle = gem_create(fd, w->bb_sz);
+	if (w->unbound_duration)
+		/* nops + MI_ARB_CHK + MI_BATCH_BUFFER_START */
+		w->bb_sz = max(64, get_bb_sz(w->preempt_us)) +
+			   (1 + 3) * sizeof(uint32_t);
+	else
+		w->bb_sz = get_bb_sz(w->duration.max);
+	w->bb_handle = w->obj[j].handle = gem_create(fd, w->bb_sz + (w->unbound_duration ? 4096 : 0));
 	init_bb(w, flags);
 	terminate_bb(w, flags);
 
-	if (flags & SEQNO) {
+	if ((flags & SEQNO) || w->unbound_duration) {
 		w->obj[j].relocs_ptr = to_user_pointer(&w->reloc);
+		if (flags & SEQNO)
+			w->obj[j].relocation_count++;
 		if (flags & RT)
-			w->obj[j].relocation_count = 4;
-		else
-			w->obj[j].relocation_count = 1;
+			w->obj[j].relocation_count += 3;
+		if (w->unbound_duration)
+			w->obj[j].relocation_count++;
 		for (i = 0; i < w->obj[j].relocation_count; i++)
 			w->reloc[i].target_handle = 1;
+		if (w->unbound_duration)
+			w->reloc[0].target_handle = j;
 	}
 
 	w->eb.buffers_ptr = to_user_pointer(w->obj);
@@ -1988,6 +2024,18 @@ update_bb_rt(struct w_step *w, enum intel_engine_id engine, uint32_t seqno)
 	}
 }
 
+static void
+update_bb_start(struct w_step *w)
+{
+	if (!w->unbound_duration)
+		return;
+
+	gem_set_domain(fd, w->bb_handle,
+		       I915_GEM_DOMAIN_WC, I915_GEM_DOMAIN_WC);
+
+	*w->recursive_bb_start = MI_BATCH_BUFFER_START | (1 << 8) | 1;
+}
+
 static void w_sync_to(struct workload *wrk, struct w_step *w, int target)
 {
 	if (target < 0)
@@ -2123,9 +2171,13 @@ do_eb(struct workload *wrk, struct w_step *w, enum intel_engine_id engine,
 	if (flags & RT)
 		update_bb_rt(w, engine, seqno);
 
+	update_bb_start(w);
+
 	w->eb.batch_start_offset =
+		w->unbound_duration ?
+		0 :
 		ALIGN(w->bb_sz - get_bb_sz(get_duration(w)),
-			2 * sizeof(uint32_t));
+		      2 * sizeof(uint32_t));
 
 	for (i = 0; i < w->fence_deps.nr; i++) {
 		int tgt = w->idx + w->fence_deps.list[i];
@@ -2265,6 +2317,17 @@ static void *run_workload(void *data)
 								    w->priority;
 				}
 				continue;
+			} else if (w->type == TERMINATE) {
+				unsigned int t_idx = i + w->target;
+
+				igt_assert(t_idx >= 0 && t_idx < i);
+				igt_assert(wrk->steps[t_idx].type == BATCH);
+				igt_assert(wrk->steps[t_idx].unbound_duration);
+
+				*wrk->steps[t_idx].recursive_bb_start =
+					MI_BATCH_BUFFER_END;
+				__sync_synchronize();
+				continue;
 			} else if (w->type == PREEMPTION ||
 				   w->type == ENGINE_MAP ||
 				   w->type == LOAD_BALANCE ||
diff --git a/benchmarks/wsim/README b/benchmarks/wsim/README
index f2974992ab68..439ea3650e3d 100644
--- a/benchmarks/wsim/README
+++ b/benchmarks/wsim/README
@@ -2,11 +2,11 @@ Workload descriptor format
 ==========================
 
 ctx.engine.duration_us.dependency.wait,...
-<uint>.<str>.<uint>[-<uint>].<int <= 0>[/<int <= 0>][...].<0|1>,...
+<uint>.<str>.<uint>[-<uint>]|*.<int <= 0>[/<int <= 0>][...].<0|1>,...
 B.<uint>
 M.<uint>.<str>[|<str>]...
 P|X.<uint>.<int>
-d|p|s|t|q|a.<int>,...
+d|p|s|t|q|a|T.<int>,...
 b.<uint>.<uint>.<str>
 f
 
@@ -30,6 +30,7 @@ Additional workload steps are also supported:
  'b' - Set up engine bonds.
  'M' - Set up engine map.
  'P' - Context priority.
+ 'T' - Terminate an infinite batch.
  'X' - Context preemption control.
 
 Engine ids: DEFAULT, RCS, BCS, VCS, VCS1, VCS2, VECS
@@ -77,6 +78,10 @@ Example:
 
 I this case the last step has a data dependency on both first and second steps.
 
+Batch durations can also be specified as infinite by using the '*' in the
+duration field. Such batches must be ended by the terminate command ('T')
+otherwise they will cause a GPU hang to be reported.
+
 Sync (fd) fences
 ----------------
 
diff --git a/benchmarks/wsim/frame-split-60fps.wsim b/benchmarks/wsim/frame-split-60fps.wsim
index cfbfcd39be7d..ea89da3add48 100644
--- a/benchmarks/wsim/frame-split-60fps.wsim
+++ b/benchmarks/wsim/frame-split-60fps.wsim
@@ -6,10 +6,12 @@ M.2.VCS2
 B.2
 b.2.1.VCS1
 f
-1.DEFAULT.4000-6000.f-1.0
+1.DEFAULT.*.f-1.0
 2.DEFAULT.4000-6000.s-1.0
 a.-3
-3.RCS.2000-4000.-3/-2.0
+s.-2
+T.-4
+3.RCS.2000-4000.-5/-4.0
 3.VECS.2000.-1.0
 4.BCS.1000.-1.0
 s.-2
-- 
2.17.1



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