[Intel-gfx] [PATCH i-g-t v6 03/12] tests/perf: update max buffer size for reading reports

[Lionel Landwerlin]

Make it clear that we're using a 16Mb buffer.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>
---
 tests/perf.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/perf.c b/tests/perf.c
index 8644e252..bd139bde 100644
--- a/tests/perf.c
+++ b/tests/perf.c
@@ -1298,9 +1298,7 @@ read_2_oa_reports(int format_id,
 	/* Note: we allocate a large buffer so that each read() iteration
 	 * should scrape *all* pending records.
 	 *
-	 * The largest buffer the OA unit supports is 16MB and the smallest
-	 * OA report format is 64bytes allowing up to 262144 reports to
-	 * be buffered.
+	 * The largest buffer the OA unit supports is 16MB.
 	 *
 	 * Being sure we are fetching all buffered reports allows us to
 	 * potentially throw away / skip all reports whenever we see
@@ -1313,7 +1311,8 @@ read_2_oa_reports(int format_id,
 	 * to indicate that the OA unit may be over taxed if lots of reports
 	 * are being lost.
 	 */
-	int buf_size = 262144 * (64 + sizeof(struct drm_i915_perf_record_header));
+	int max_reports = (16 * 1024 * 1024) / format_size;
+	int buf_size = sample_size * max_reports * 1.5;
 	uint8_t *buf = malloc(buf_size);
 	int n = 0;
 
@@ -1325,6 +1324,7 @@ read_2_oa_reports(int format_id,
 			;
 
 		igt_assert(len > 0);
+		igt_debug("read %d bytes\n", (int)len);
 
 		for (size_t offset = 0; offset < len; offset += header->size) {
 			const uint32_t *report;
-- 
2.14.2