lib: Shrink all i915 caches before measuring avail memory

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

lib/intel_os.c

@@ -51,6 +51,7 @@
 #include "intel_io.h"
 #include "drmtest.h"
 #include "igt_aux.h"
+#include "igt_debugfs.h"
 
 /**
  * intel_get_total_ram_mb:
@@ -295,6 +296,8 @@ void intel_purge_vm_caches(void)
 {
 	int fd;
 
+	igt_drop_caches_set(DROP_SHRINK_ALL);
+
 	fd = open("/proc/sys/vm/drop_caches", O_WRONLY);
 	if (fd >= 0) {
 		/* BIT(2): Be quiet. Cannot be combined with other operations,