[PATCH i-g-t] tests/intel/xe_evict: Reduce allocations to maximum working set

[Thomas Hellström]

Current xe kmd allows for a maximum working set of VRAM plus
half of system memory, or if the working set is allowed only in
VRAM, the working set is limited to VRAM.

Some subtests attempt to exceed that. Detect when that happens
and limit the working set accordingly.

Cc: Matthew Brost <matthew.brost at intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 tests/intel/xe_evict.c | 72 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 59 insertions(+), 13 deletions(-)

diff --git a/tests/intel/xe_evict.c b/tests/intel/xe_evict.c
index eebdbc84b..af5e5e5b6 100644
--- a/tests/intel/xe_evict.c
+++ b/tests/intel/xe_evict.c
@@ -458,6 +458,33 @@ static uint64_t calc_bo_size(uint64_t vram_size, int mul, int div)
 		return (ALIGN(vram_size, SZ_256M)  * mul) / div; /* small-bar */
 }
 
+static unsigned int working_set(uint64_t vram_size, uint64_t system_size,
+				uint64_t bo_size, unsigned int num_threads,
+				unsigned int flags)
+{
+	uint64_t set_size;
+	uint64_t total_size;
+
+	set_size = (vram_size - 1) / bo_size;
+
+	/*
+	 * Working set resizes also in system?
+	 * Currently system graphics memory is limited to 50% of total.
+	 */
+	if (!(flags & !(THREADED | MULTI_VM)))
+		set_size += (system_size / 2) / bo_size;
+
+	/* All bos must fit in memory, assuming no swapping */
+	total_size = ((vram_size - 1) / bo_size + system_size / bo_size) /
+		num_threads;
+
+	if (set_size > total_size)
+		set_size = total_size;
+
+	/* bos are only created on half of the execs. */
+	return set_size * 2;
+}
+
 /**
  * SUBTEST: evict-%s
  * Description:  %arg[1] evict test.
@@ -748,6 +775,7 @@ igt_main
 		{ NULL },
 	};
 	uint64_t vram_size;
+	uint64_t system_size;
 	int fd;
 
 	igt_fixture {
@@ -755,14 +783,16 @@ igt_main
 		igt_require(xe_has_vram(fd));
 		vram_size = xe_visible_vram_size(fd, 0);
 		igt_assert(vram_size);
+		system_size = igt_get_avail_ram_mb() << 20;
 
 		/* Test requires SRAM to about as big as VRAM. For example, small-cm creates
 		 * (448 / 2) BOs with a size (1 / 128) of the total VRAM size. For
 		 * simplicity ensure the SRAM size >= VRAM before running this test.
 		 */
-		igt_skip_on_f(igt_get_avail_ram_mb() < (vram_size >> 20),
-			      "System memory %lu MiB is less than local memory %lu MiB\n",
-			      igt_get_avail_ram_mb(), vram_size >> 20);
+		igt_skip_on_f(system_size < vram_size,
+			      "System memory %llu MiB is less than local memory %llu MiB\n",
+			      (unsigned long long)system_size >> 20,
+			      (unsigned long long)vram_size >> 20);
 
 		xe_for_each_engine(fd, hwe)
 			if (hwe->engine_class != DRM_XE_ENGINE_CLASS_COPY)
@@ -770,25 +800,41 @@ igt_main
 	}
 
 	for (const struct section *s = sections; s->name; s++) {
-		igt_subtest_f("evict-%s", s->name)
-			test_evict(fd, hwe, s->n_exec_queues, s->n_execs,
-				   calc_bo_size(vram_size, s->mul, s->div),
+		igt_subtest_f("evict-%s", s->name) {
+			uint64_t bo_size = calc_bo_size(vram_size, s->mul, s->div);
+			int ws = working_set(vram_size, system_size, bo_size,
+					     1, s->flags);
+
+			igt_debug("Max working set %d n_execs %d\n", ws, s->n_execs);
+			test_evict(fd, hwe, s->n_exec_queues,
+				   min(ws, s->n_execs), bo_size,
 				   s->flags, NULL);
+		}
 	}
 
 	for (const struct section_cm *s = sections_cm; s->name; s++) {
-		igt_subtest_f("evict-%s", s->name)
-			test_evict_cm(fd, hwe, s->n_exec_queues, s->n_execs,
-				      calc_bo_size(vram_size, s->mul, s->div),
+		igt_subtest_f("evict-%s", s->name) {
+			uint64_t bo_size = calc_bo_size(vram_size, s->mul, s->div);
+			int ws = working_set(vram_size, system_size, bo_size,
+					     1, s->flags);
+
+			igt_debug("Max working set %d n_execs %d\n", ws, s->n_execs);
+			test_evict_cm(fd, hwe, s->n_exec_queues,
+				      min(ws, s->n_execs), bo_size,
 				      s->flags, NULL);
+		}
 	}
 
 	for (const struct section_threads *s = sections_threads; s->name; s++) {
-		igt_subtest_f("evict-%s", s->name)
+		igt_subtest_f("evict-%s", s->name) {
+			uint64_t bo_size = calc_bo_size(vram_size, s->mul, s->div);
+			int ws = working_set(vram_size, system_size, bo_size,
+					     s->n_threads, s->flags);
+
+			igt_debug("Max working set %d n_execs %d\n", ws, s->n_execs);
 			threads(fd, hwe, s->n_threads, s->n_exec_queues,
-				 s->n_execs,
-				 calc_bo_size(vram_size, s->mul, s->div),
-				 s->flags);
+				min(ws, s->n_execs), bo_size, s->flags);
+		}
 	}
 
 	igt_fixture
-- 
2.44.0