2022-10-21 16:56:29

by James Houghton

[permalink] [raw]
Subject: [RFC PATCH v2 45/47] selftests/vm: add anon and shared hugetlb to migration test

Shared HugeTLB mappings are migrated best-effort. Sometimes, due to
being unable to grab the VMA lock for writing, migration may just
randomly fail. To allow for that, we allow retries.

Signed-off-by: James Houghton <[email protected]>
---
tools/testing/selftests/vm/migration.c | 83 ++++++++++++++++++++++++--
1 file changed, 79 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vm/migration.c b/tools/testing/selftests/vm/migration.c
index 1cec8425e3ca..21577a84d7e4 100644
--- a/tools/testing/selftests/vm/migration.c
+++ b/tools/testing/selftests/vm/migration.c
@@ -13,6 +13,7 @@
#include <sys/types.h>
#include <signal.h>
#include <time.h>
+#include <sys/statfs.h>

#define TWOMEG (2<<20)
#define RUNTIME (60)
@@ -59,11 +60,12 @@ FIXTURE_TEARDOWN(migration)
free(self->pids);
}

-int migrate(uint64_t *ptr, int n1, int n2)
+int migrate(uint64_t *ptr, int n1, int n2, int retries)
{
int ret, tmp;
int status = 0;
struct timespec ts1, ts2;
+ int failed = 0;

if (clock_gettime(CLOCK_MONOTONIC, &ts1))
return -1;
@@ -78,6 +80,9 @@ 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 (++failed < retries)
+ continue;
+
if (ret > 0)
printf("Didn't migrate %d pages\n", ret);
else
@@ -88,6 +93,7 @@ int migrate(uint64_t *ptr, int n1, int n2)
tmp = n2;
n2 = n1;
n1 = tmp;
+ failed = 0;
}

return 0;
@@ -128,7 +134,7 @@ TEST_F_TIMEOUT(migration, private_anon, 2*RUNTIME)
if (pthread_create(&self->threads[i], NULL, access_mem, ptr))
perror("Couldn't create thread");

- ASSERT_EQ(migrate(ptr, self->n1, self->n2), 0);
+ ASSERT_EQ(migrate(ptr, self->n1, self->n2, 1), 0);
for (i = 0; i < self->nthreads - 1; i++)
ASSERT_EQ(pthread_cancel(self->threads[i]), 0);
}
@@ -158,7 +164,7 @@ TEST_F_TIMEOUT(migration, shared_anon, 2*RUNTIME)
self->pids[i] = pid;
}

- ASSERT_EQ(migrate(ptr, self->n1, self->n2), 0);
+ ASSERT_EQ(migrate(ptr, self->n1, self->n2, 1), 0);
for (i = 0; i < self->nthreads - 1; i++)
ASSERT_EQ(kill(self->pids[i], SIGTERM), 0);
}
@@ -185,9 +191,78 @@ TEST_F_TIMEOUT(migration, private_anon_thp, 2*RUNTIME)
if (pthread_create(&self->threads[i], NULL, access_mem, ptr))
perror("Couldn't create thread");

- ASSERT_EQ(migrate(ptr, self->n1, self->n2), 0);
+ ASSERT_EQ(migrate(ptr, self->n1, self->n2, 1), 0);
+ for (i = 0; i < self->nthreads - 1; i++)
+ ASSERT_EQ(pthread_cancel(self->threads[i]), 0);
+}
+
+/*
+ * Tests the anon hugetlb migration entry paths.
+ */
+TEST_F_TIMEOUT(migration, private_anon_hugetlb, 2*RUNTIME)
+{
+ uint64_t *ptr;
+ int i;
+
+ if (self->nthreads < 2 || self->n1 < 0 || self->n2 < 0)
+ SKIP(return, "Not enough threads or NUMA nodes available");
+
+ ptr = mmap(NULL, TWOMEG, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
+ if (ptr == MAP_FAILED)
+ SKIP(return, "Could not allocate hugetlb pages");
+
+ memset(ptr, 0xde, TWOMEG);
+ for (i = 0; i < self->nthreads - 1; i++)
+ if (pthread_create(&self->threads[i], NULL, access_mem, ptr))
+ perror("Couldn't create thread");
+
+ ASSERT_EQ(migrate(ptr, self->n1, self->n2, 1), 0);
for (i = 0; i < self->nthreads - 1; i++)
ASSERT_EQ(pthread_cancel(self->threads[i]), 0);
}

+/*
+ * Tests the shared hugetlb migration entry paths.
+ */
+TEST_F_TIMEOUT(migration, shared_hugetlb, 2*RUNTIME)
+{
+ uint64_t *ptr;
+ int i;
+ int fd;
+ unsigned long sz;
+ struct statfs filestat;
+
+ if (self->nthreads < 2 || self->n1 < 0 || self->n2 < 0)
+ SKIP(return, "Not enough threads or NUMA nodes available");
+
+ fd = memfd_create("tmp_hugetlb", MFD_HUGETLB);
+ if (fd < 0)
+ SKIP(return, "Couldn't create hugetlb memfd");
+
+ if (fstatfs(fd, &filestat) < 0)
+ SKIP(return, "Couldn't fstatfs hugetlb file");
+
+ sz = filestat.f_bsize;
+
+ if (ftruncate(fd, sz))
+ SKIP(return, "Couldn't allocate hugetlb pages");
+ ptr = mmap(NULL, sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (ptr == MAP_FAILED)
+ SKIP(return, "Could not map hugetlb pages");
+
+ memset(ptr, 0xde, sz);
+ for (i = 0; i < self->nthreads - 1; i++)
+ if (pthread_create(&self->threads[i], NULL, access_mem, ptr))
+ perror("Couldn't create thread");
+
+ ASSERT_EQ(migrate(ptr, self->n1, self->n2, 10), 0);
+ for (i = 0; i < self->nthreads - 1; i++) {
+ ASSERT_EQ(pthread_cancel(self->threads[i]), 0);
+ pthread_join(self->threads[i], NULL);
+ }
+ ftruncate(fd, 0);
+ close(fd);
+}
+
TEST_HARNESS_MAIN
--
2.38.0.135.g90850a2211-goog