Factor in kernel object overhead when checking available memory for tests

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

2 files changed, 34 insertions, 0 deletions

diff --git a/lib/igt_aux.h b/lib/igt_aux.h
index 597580da..db0dea84 100644
--- a/lib/igt_aux.h
+++ b/lib/igt_aux.h
@@ -77,4 +77,8 @@ uint64_t intel_get_avail_ram_mb(void);
 uint64_t intel_get_total_ram_mb(void);
 uint64_t intel_get_total_swap_mb(void);
 
+bool intel_check_memory(uint32_t count, uint32_t size, unsigned mode);
+#define CHECK_RAM 0x1
+#define CHECK_SWAP 0x2
+
 #endif /* IGT_AUX_H */
diff --git a/lib/intel_os.c b/lib/intel_os.c
index 7d9a703a..e717c7b5 100644
--- a/lib/intel_os.c
+++ b/lib/intel_os.c
@@ -185,6 +185,36 @@ intel_get_total_swap_mb(void)
 	return retval / (1024*1024);
 }
 
+bool intel_check_memory(uint32_t count, uint32_t size, unsigned mode)
+{
+/* rough estimate of how many bytes the kernel requires to track each object */
+#define KERNEL_BO_OVERHEAD 512
+	uint64_t required, total;
+
+	required = count;
+	required *= size + KERNEL_BO_OVERHEAD;
+	required = ALIGN(required, 4096);
+
+	total = 0;
+	if (mode & (CHECK_RAM | CHECK_SWAP))
+		total += intel_get_avail_ram_mb();
+	if (mode & CHECK_SWAP)
+		total += intel_get_total_swap_mb();
+	total *= 1024 * 1024;
+
+	if (total <= required) {
+		igt_log(IGT_LOG_INFO,
+			"Estimated that we need %llu bytes for the test, but only have %llu bytes available (%s%s)\n",
+			(long long)required, (long long)total,
+			mode & CHECK_RAM ? "RAM" : "",
+			mode & CHECK_SWAP ? " + swap": "");
+		return 0;
+	}
+
+	return 1;
+}
+
+
 void
 intel_purge_vm_caches(void)
 {