mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-31 14:04:27 -04:00
Code Issues Packages Projects Releases Wiki Activity

selftests/mm: retry migration failures for the full runtime

Browse Source 
move_pages() is best effort and can temporarily fail when concurrent
faults race with page unmapping.  A busy shared-anon workload can exhaust
the current 100 retries long before the intended 20-second runtime and
produce a false failure.

Use the full runtime as the retry window.  Since the initial page location
is unknown, require it to reach both alternating NUMA targets to confirm
that cross-node migration made progress despite transient contention.

Link: https://lore.kernel.org/20260727095225.372655-6-usama.anjum@arm.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sarthak Sharma <sarthak.sharma@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Muhammad Usama Anjum
2026-07-27 10:52:21 +01:00
committed by Andrew Morton
parent e14e52a7ce
commit 746c94b7cb
1 changed files with 20 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
tools/testing/selftests/mm/migration.c
View File

@@ -7,7 +7,7 @@
#include "kselftest_harness.h"
#include "hugepage_settings.h"
#include <strings.h>
#include <string.h>
#include <pthread.h>
#include <numa.h>
#include <numaif.h>
@@ -20,7 +20,6 @@
#define TWOMEG (2<<20)
#define RUNTIME (20)
#define MAX_RETRIES 100
#define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1)))
HUGETLB_SETUP_DEFAULT_PAGES(1)
@@ -110,7 +109,7 @@ int migrate(uint64_t *ptr, int n1, int n2)
int ret, tmp;
int status = 0;
struct timespec ts1, ts2;
int failures = 0;
int success = 0;
if (clock_gettime(CLOCK_MONOTONIC, &ts1))
return -1;
@@ -119,29 +118,33 @@ int migrate(uint64_t *ptr, int n1, int n2)
if (clock_gettime(CLOCK_MONOTONIC, &ts2))
return -1;
if (ts2.tv_sec - ts1.tv_sec >= RUNTIME)
return 0;
if (ts2.tv_sec - ts1.tv_sec >= RUNTIME) {
/* Reaching both targets verifies a cross-node move. */
if (success >= 2)
return 0;
else
return -2;
}
ret = move_pages(0, 1, (void **) &ptr, &n2, &status,
MPOL_MF_MOVE_ALL);
if (ret) {
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");
if (ret < 0) {
perror("Couldn't migrate pages");
return ret;
}
/* Migration is best effort. Try again */
if (ret > 0 || status < 0)
continue;
if (status != n2) {
printf("Page is on node %d instead of target node %d\n",
status, n2);
return -2;
}
failures = 0;
success++;
tmp = n2;
n2 = n1;
n1 = tmp;
}
return 0;
}
void *access_mem(void *ptr)