| Message ID | 99a3e190d38b08a2b96ede952a29893bffdb3432.1742960003.git.baolin.wang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fix mincore() tmpfs test failure | expand |
On 25 Mar 2025, at 23:38, Baolin Wang wrote: > When running mincore test cases, I encountered the following failures: > > " > mincore_selftest.c:359:check_tmpfs_mmap:Expected ra_pages (511) == 0 (0) > mincore_selftest.c:360:check_tmpfs_mmap:Read-ahead pages found in memory > check_tmpfs_mmap: Test terminated by assertion > FAIL global.check_tmpfs_mmap > not ok 5 global.check_tmpfs_mmap > FAILED: 4 / 5 tests passed > " > > The reason for the test case failure is that my system automatically enabled > tmpfs large folio allocation by adding the 'transparent_hugepage_tmpfs=always' > cmdline. However, the test case still expects the tmpfs mounted on /dev/shm to > allocate small folios, which leads to assertion failures when verifying readahead > pages. > > To fix this issue, remount tmpfs to a new test directory and set the 'huge=never' > parameter to avoid allocating large folios, which can pass the test. > > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> > --- > .../selftests/mincore/mincore_selftest.c | 25 +++++++++++++++++-- > 1 file changed, 23 insertions(+), 2 deletions(-) > <snip> > > errno = 0; > - fd = open("/dev/shm", O_TMPFILE | O_RDWR, 0600); > + /* Do not use large folios for tmpfs mincore testing */ > + retval = mount("tmpfs", tmpfs_loc, "tmpfs", 0, "huge=never,size=4M"); > + ASSERT_EQ(0, retval) { > + TH_LOG("Unable to mount tmpfs for testing\n"); > + } > + > + retval = snprintf(testfile, INPUT_MAX, "%s/test_file", tmpfs_loc); > + ASSERT_GE(INPUT_MAX, retval) { > + TH_LOG("Unable to create a tmpfs for testing\n"); > + } > + > + fd = open(testfile, O_CREAT|O_RDWR, 0664); The fd permission is changed from 0600 to 0664, but it probably does not matter. > ASSERT_NE(-1, fd) { > TH_LOG("Can't create temporary file: %s", > strerror(errno)); > @@ -363,6 +382,8 @@ TEST(check_tmpfs_mmap) > munmap(addr, FILE_SIZE); > close(fd); > free(vec); > + umount(tmpfs_loc); > + rmdir(tmpfs_loc); > } > > TEST_HARNESS_MAIN > -- > 2.43.5 Otherwise, LGTM. Reviewed-by: Zi Yan <ziy@nvidia.com> -- Best Regards, Yan, Zi
On 2025/3/27 22:36, Zi Yan wrote: > On 25 Mar 2025, at 23:38, Baolin Wang wrote: > >> When running mincore test cases, I encountered the following failures: >> >> " >> mincore_selftest.c:359:check_tmpfs_mmap:Expected ra_pages (511) == 0 (0) >> mincore_selftest.c:360:check_tmpfs_mmap:Read-ahead pages found in memory >> check_tmpfs_mmap: Test terminated by assertion >> FAIL global.check_tmpfs_mmap >> not ok 5 global.check_tmpfs_mmap >> FAILED: 4 / 5 tests passed >> " >> >> The reason for the test case failure is that my system automatically enabled >> tmpfs large folio allocation by adding the 'transparent_hugepage_tmpfs=always' >> cmdline. However, the test case still expects the tmpfs mounted on /dev/shm to >> allocate small folios, which leads to assertion failures when verifying readahead >> pages. >> >> To fix this issue, remount tmpfs to a new test directory and set the 'huge=never' >> parameter to avoid allocating large folios, which can pass the test. >> >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> >> --- >> .../selftests/mincore/mincore_selftest.c | 25 +++++++++++++++++-- >> 1 file changed, 23 insertions(+), 2 deletions(-) >> > > <snip> > >> >> errno = 0; >> - fd = open("/dev/shm", O_TMPFILE | O_RDWR, 0600); >> + /* Do not use large folios for tmpfs mincore testing */ >> + retval = mount("tmpfs", tmpfs_loc, "tmpfs", 0, "huge=never,size=4M"); >> + ASSERT_EQ(0, retval) { >> + TH_LOG("Unable to mount tmpfs for testing\n"); >> + } >> + >> + retval = snprintf(testfile, INPUT_MAX, "%s/test_file", tmpfs_loc); >> + ASSERT_GE(INPUT_MAX, retval) { >> + TH_LOG("Unable to create a tmpfs for testing\n"); >> + } >> + >> + fd = open(testfile, O_CREAT|O_RDWR, 0664); > > The fd permission is changed from 0600 to 0664, but it probably does not > matter. It is just a temp file, so it doesn't matter. > >> ASSERT_NE(-1, fd) { >> TH_LOG("Can't create temporary file: %s", >> strerror(errno)); >> @@ -363,6 +382,8 @@ TEST(check_tmpfs_mmap) >> munmap(addr, FILE_SIZE); >> close(fd); >> free(vec); >> + umount(tmpfs_loc); >> + rmdir(tmpfs_loc); >> } >> >> TEST_HARNESS_MAIN >> -- >> 2.43.5 > > Otherwise, LGTM. Reviewed-by: Zi Yan <ziy@nvidia.com> Thanks for reviewing.
On 26.03.25 04:38, Baolin Wang wrote: > When running mincore test cases, I encountered the following failures: > > " > mincore_selftest.c:359:check_tmpfs_mmap:Expected ra_pages (511) == 0 (0) > mincore_selftest.c:360:check_tmpfs_mmap:Read-ahead pages found in memory > check_tmpfs_mmap: Test terminated by assertion > FAIL global.check_tmpfs_mmap > not ok 5 global.check_tmpfs_mmap > FAILED: 4 / 5 tests passed > " > > The reason for the test case failure is that my system automatically enabled > tmpfs large folio allocation by adding the 'transparent_hugepage_tmpfs=always' > cmdline. However, the test case still expects the tmpfs mounted on /dev/shm to > allocate small folios, which leads to assertion failures when verifying readahead > pages. > > To fix this issue, remount tmpfs to a new test directory and set the 'huge=never' > parameter to avoid allocating large folios, which can pass the test. > > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> > --- > .../selftests/mincore/mincore_selftest.c | 25 +++++++++++++++++-- > 1 file changed, 23 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/mincore/mincore_selftest.c b/tools/testing/selftests/mincore/mincore_selftest.c > index e949a43a6145..e8d7a3a4739f 100644 > --- a/tools/testing/selftests/mincore/mincore_selftest.c > +++ b/tools/testing/selftests/mincore/mincore_selftest.c > @@ -12,6 +12,7 @@ > #include <unistd.h> > #include <stdlib.h> > #include <sys/mman.h> > +#include <sys/mount.h> > #include <string.h> > #include <fcntl.h> > > @@ -283,7 +284,7 @@ TEST(check_file_mmap) > free(vec); > } > > - > +#define INPUT_MAX 80 > /* > * Test mincore() behavior on a page backed by a tmpfs file. This test > * performs the same steps as the previous one. However, we don't expect > @@ -291,6 +292,9 @@ TEST(check_file_mmap) > */ > TEST(check_tmpfs_mmap) > { > + char tmpfs_template[] = "/tmp/check_tmpfs_XXXXXX"; > + const char *tmpfs_loc = mkdtemp(tmpfs_template); > + char testfile[INPUT_MAX]; > unsigned char *vec; > int vec_size; > char *addr; > @@ -300,6 +304,10 @@ TEST(check_tmpfs_mmap) > int i; > int ra_pages = 0; > > + ASSERT_NE(NULL, tmpfs_loc) { > + TH_LOG("Can't mkdir tmpfs dentry\n"); > + } > + > page_size = sysconf(_SC_PAGESIZE); > vec_size = FILE_SIZE / page_size; > if (FILE_SIZE % page_size) > @@ -311,7 +319,18 @@ TEST(check_tmpfs_mmap) > } > > errno = 0; > - fd = open("/dev/shm", O_TMPFILE | O_RDWR, 0600); > + /* Do not use large folios for tmpfs mincore testing */ > + retval = mount("tmpfs", tmpfs_loc, "tmpfs", 0, "huge=never,size=4M"); > + ASSERT_EQ(0, retval) { > + TH_LOG("Unable to mount tmpfs for testing\n"); > + } > + > + retval = snprintf(testfile, INPUT_MAX, "%s/test_file", tmpfs_loc); > + ASSERT_GE(INPUT_MAX, retval) { > + TH_LOG("Unable to create a tmpfs for testing\n"); > + } > + > + fd = open(testfile, O_CREAT|O_RDWR, 0664); > ASSERT_NE(-1, fd) { > TH_LOG("Can't create temporary file: %s", > strerror(errno)); > @@ -363,6 +382,8 @@ TEST(check_tmpfs_mmap) > munmap(addr, FILE_SIZE); > close(fd); > free(vec); > + umount(tmpfs_loc); > + rmdir(tmpfs_loc); > } > > TEST_HARNESS_MAIN Is there anything that cleans up the mount in case something goes wrong (we run into an assertion), or will the directory+mount stick around forever? But I also wonder whether check_tmpfs_mmap() should be changed to live with the fact that readahead ("faultaround") could now happen. What's the reason for not doing that?
diff --git a/tools/testing/selftests/mincore/mincore_selftest.c b/tools/testing/selftests/mincore/mincore_selftest.c index e949a43a6145..e8d7a3a4739f 100644 --- a/tools/testing/selftests/mincore/mincore_selftest.c +++ b/tools/testing/selftests/mincore/mincore_selftest.c @@ -12,6 +12,7 @@ #include <unistd.h> #include <stdlib.h> #include <sys/mman.h> +#include <sys/mount.h> #include <string.h> #include <fcntl.h> @@ -283,7 +284,7 @@ TEST(check_file_mmap) free(vec); } - +#define INPUT_MAX 80 /* * Test mincore() behavior on a page backed by a tmpfs file. This test * performs the same steps as the previous one. However, we don't expect @@ -291,6 +292,9 @@ TEST(check_file_mmap) */ TEST(check_tmpfs_mmap) { + char tmpfs_template[] = "/tmp/check_tmpfs_XXXXXX"; + const char *tmpfs_loc = mkdtemp(tmpfs_template); + char testfile[INPUT_MAX]; unsigned char *vec; int vec_size; char *addr; @@ -300,6 +304,10 @@ TEST(check_tmpfs_mmap) int i; int ra_pages = 0; + ASSERT_NE(NULL, tmpfs_loc) { + TH_LOG("Can't mkdir tmpfs dentry\n"); + } + page_size = sysconf(_SC_PAGESIZE); vec_size = FILE_SIZE / page_size; if (FILE_SIZE % page_size) @@ -311,7 +319,18 @@ TEST(check_tmpfs_mmap) } errno = 0; - fd = open("/dev/shm", O_TMPFILE | O_RDWR, 0600); + /* Do not use large folios for tmpfs mincore testing */ + retval = mount("tmpfs", tmpfs_loc, "tmpfs", 0, "huge=never,size=4M"); + ASSERT_EQ(0, retval) { + TH_LOG("Unable to mount tmpfs for testing\n"); + } + + retval = snprintf(testfile, INPUT_MAX, "%s/test_file", tmpfs_loc); + ASSERT_GE(INPUT_MAX, retval) { + TH_LOG("Unable to create a tmpfs for testing\n"); + } + + fd = open(testfile, O_CREAT|O_RDWR, 0664); ASSERT_NE(-1, fd) { TH_LOG("Can't create temporary file: %s", strerror(errno)); @@ -363,6 +382,8 @@ TEST(check_tmpfs_mmap) munmap(addr, FILE_SIZE); close(fd); free(vec); + umount(tmpfs_loc); + rmdir(tmpfs_loc); } TEST_HARNESS_MAIN
When running mincore test cases, I encountered the following failures: " mincore_selftest.c:359:check_tmpfs_mmap:Expected ra_pages (511) == 0 (0) mincore_selftest.c:360:check_tmpfs_mmap:Read-ahead pages found in memory check_tmpfs_mmap: Test terminated by assertion FAIL global.check_tmpfs_mmap not ok 5 global.check_tmpfs_mmap FAILED: 4 / 5 tests passed " The reason for the test case failure is that my system automatically enabled tmpfs large folio allocation by adding the 'transparent_hugepage_tmpfs=always' cmdline. However, the test case still expects the tmpfs mounted on /dev/shm to allocate small folios, which leads to assertion failures when verifying readahead pages. To fix this issue, remount tmpfs to a new test directory and set the 'huge=never' parameter to avoid allocating large folios, which can pass the test. Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> --- .../selftests/mincore/mincore_selftest.c | 25 +++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-)