Messages in this thread Patches in this message | | | Date | Tue, 23 May 2023 12:15:02 +0200 | From | David Hildenbrand <> | Subject | Re: [PATCH v8 6/6] selftest: add a testcase of ksm zero pages |
| |
On 22.05.23 12:54, Yang Yang wrote: > From: xu xin <xu.xin16@zte.com.cn> > > Add a function test_unmerge_zero_page() to test the functionality on > unsharing and counting ksm-placed zero pages and counting of this patch > series. > > test_unmerge_zero_page() actually contains three subjct test objects: > (1) whether the count of ksm zero pages can update correctly after merging; > (2) whether the count of ksm zero pages can update correctly after > unmerging; > (3) whether ksm zero pages are really unmerged. > > Signed-off-by: xu xin <xu.xin16@zte.com.cn> > Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn> > Reviewed-by: Xiaokai Ran <ran.xiaokai@zte.com.cn> > Reviewed-by: Yang Yang <yang.yang29@zte.com.cn> > --- > tools/testing/selftests/mm/ksm_functional_tests.c | 75 +++++++++++++++++++++++ > 1 file changed, 75 insertions(+) > > diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c > index 26853badae70..9b7fb94ed64f 100644 > --- a/tools/testing/selftests/mm/ksm_functional_tests.c > +++ b/tools/testing/selftests/mm/ksm_functional_tests.c > @@ -29,6 +29,8 @@ > > static int ksm_fd; > static int ksm_full_scans_fd; > +static int ksm_zero_pages_fd; > +static int ksm_use_zero_pages_fd; > static int pagemap_fd; > static size_t pagesize; > > @@ -59,6 +61,21 @@ static bool range_maps_duplicates(char *addr, unsigned long size) > return false; > } > > +static long get_ksm_zero_pages(void) > +{ > + char buf[20]; > + ssize_t read_size; > + unsigned long ksm_zero_pages; > +
I would add:
if (!ksm_zero_pages_fd) return 0;
> + read_size = pread(ksm_zero_pages_fd, buf, sizeof(buf) - 1, 0); > + if (read_size < 0) > + return -errno; > + buf[read_size] = 0; > + ksm_zero_pages = strtol(buf, NULL, 10); > + > + return ksm_zero_pages; > +} > + > static long ksm_get_full_scans(void) > { > char buf[10]; > @@ -159,6 +176,61 @@ static void test_unmerge(void) > munmap(map, size); > } > > +static inline unsigned long expected_ksm_pages(unsigned long mergeable_size) > +{ > + return mergeable_size / pagesize; > +}
I suggest to just inline that.
> + > +static void test_unmerge_zero_pages(void) > +{ > + const unsigned int size = 2 * MiB; > + char *map; > + unsigned long pages_expected; > + > + ksft_print_msg("[RUN] %s\n", __func__); > + > + /* Confirm the interfaces*/
Missing space at the end of the comment. But I suggest to just drop this comment.
> + if (ksm_zero_pages_fd < 0) { > + ksft_test_result_skip("open(\"/sys/kernel/mm/ksm/ksm_zero_pages\") failed\n"); > + return; > + } > + if (ksm_use_zero_pages_fd < 0) { > + ksft_test_result_skip("open \"/sys/kernel/mm/ksm/use_zero_pages\" failed\n"); > + return; > + } > + if (write(ksm_use_zero_pages_fd, "1", 1) != 1) { > + ksft_test_result_skip("write \"/sys/kernel/mm/ksm/use_zero_pages\" failed\n"); > + return; > + } > + > + /* Mmap zero pages*/
Missing space at the end of the comment
> + map = mmap_and_merge_range(0x00, size, false); > + if (map == MAP_FAILED) > + return; > + > + /* Check if ksm_zero_pages can be update correctly after merging */ > + pages_expected = expected_ksm_pages(size); > + ksft_test_result(pages_expected == get_ksm_zero_pages(), > + "The count zero_page_sharing was updated after merging\n"); > + Make sure that the number of tests (ksft_test_result*() invocations) is on any return path as expected (e.g., 1).
if (pages_expected != get_ksm_zero_pages) { ksft_test_result_pass("'zero_page_sharing' updated after merging\n"); goto unmap; } > + /* try to unmerge half of the region */ > + if (madvise(map, size / 2, MADV_UNMERGEABLE)) { > + ksft_test_result_fail("MADV_UNMERGEABLE failed\n"); > + goto unmap; > + } > + > + /* Check if ksm_zero_pages can be update correctly after unmerging */ > + pages_expected = expected_ksm_pages(size / 2);
Just do
pages_expected /= 2;
> + ksft_test_result(pages_expected == get_ksm_zero_pages(), > + "The count zero_page_sharing was updated after unmerging\n"); > +
if (pages_expected == get_ksm_zero_pages()) { ksft_test_result_pass("'zero_page_sharing' updated after unmerging\n"); goto unmap; } > + /* Check if ksm zero pages are really unmerged */ > + ksft_test_result(!range_maps_duplicates(map, size / 2), > + "KSM zero pages were unmerged\n"); > +unmap: > + munmap(map, size); > +} > + > static void test_unmerge_discarded(void) > { > const unsigned int size = 2 * MiB; > @@ -379,8 +451,11 @@ int main(int argc, char **argv) > pagemap_fd = open("/proc/self/pagemap", O_RDONLY); > if (pagemap_fd < 0) > ksft_exit_skip("open(\"/proc/self/pagemap\") failed\n"); > + ksm_zero_pages_fd = open("/sys/kernel/mm/ksm/ksm_zero_pages", O_RDONLY); > + ksm_use_zero_pages_fd = open("/sys/kernel/mm/ksm/use_zero_pages", O_RDWR); > > test_unmerge(); > + test_unmerge_zero_pages(); > test_unmerge_discarded(); > #ifdef __NR_userfaultfd > test_unmerge_uffd_wp();
You should need something like this:
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c index 26853badae70..00df05bfc3a3 100644 --- a/tools/testing/selftests/mm/ksm_functional_tests.c +++ b/tools/testing/selftests/mm/ksm_functional_tests.c @@ -358,7 +358,7 @@ static void test_prctl_unmerge(void) int main(int argc, char **argv) { - unsigned int tests = 5; + unsigned int tests = 6; int err; #ifdef __NR_userfaultfd -- Thanks,
David / dhildenb
| |