On 8/9/24 04:31, Dev Jain wrote:
Do not fail the test for just a single instance of migration failure,
since migration is a best-effort service.
The cover letter says:
"Given that migration is a best-effort service, it is wrong to fail the
test for just a single failure; hence, fail the test after 100 consecutive
failures (where 100 is still a subjective choice)."
You do want to mention the above here.
The reason being, I would like to know what this does to the run-time of
this test if migration fails and retried 100 times.
Signed-off-by: Dev Jain <dev.jain@xxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Tested-by: Ryan Roberts <ryan.roberts@xxxxxxx>
---
tools/testing/selftests/mm/migration.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c
index 6908569ef406..64bcbb7151cf 100644
--- a/tools/testing/selftests/mm/migration.c
+++ b/tools/testing/selftests/mm/migration.c
@@ -15,10 +15,10 @@
#include <signal.h>
#include <time.h>
-#define TWOMEG (2<<20)
-#define RUNTIME (20)
-
-#define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1)))
+#define TWOMEG (2<<20)
+#define RUNTIME (20)
+#define MAX_RETRIES 100
+#define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1)))
FIXTURE(migration)
{
@@ -65,6 +65,7 @@ int migrate(uint64_t *ptr, int n1, int n2)
int ret, tmp;
int status = 0;
struct timespec ts1, ts2;
+ int failures = 0;
if (clock_gettime(CLOCK_MONOTONIC, &ts1))
return -1;
@@ -79,13 +80,17 @@ int migrate(uint64_t *ptr, int n1, int n2)
ret = move_pages(0, 1, (void **) &ptr, &n2, &status,
MPOL_MF_MOVE_ALL);
if (ret) {
- if (ret > 0)
+ if (ret > 0) {
+ /* Migration is best effort; try again */
+ if (++failures < MAX_RETRIES)
+ continue;
printf("Didn't migrate %d pages\n", ret);
+ }
else
perror("Couldn't migrate pages");
return -2;
}
-
+ failures = 0;
tmp = n2;
n2 = n1;
n1 = tmp;
thanks,
-- Shuah
