Add tests for the improvement made to read operation on HWPOISON
hugetlb page with different read granularities. For each chunk size,
three read scenarios are tested:
1. Simple regression test on read without HWPOISON.
2. Sequential read page by page should succeed until encounters the 1st
raw HWPOISON subpage.
3. After skip a raw HWPOISON subpage by lseek, read()s always succeed.
Acked-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Signed-off-by: Jiaqi Yan <jiaqiyan@xxxxxxxxxx>
---
tools/testing/selftests/mm/.gitignore | 1 +
tools/testing/selftests/mm/Makefile | 1 +
.../selftests/mm/hugetlb-read-hwpoison.c | 322 ++++++++++++++++++
3 files changed, 324 insertions(+)
create mode 100644 tools/testing/selftests/mm/hugetlb-read-hwpoison.c
diff --git a/tools/testing/selftests/mm/.gitignore b/tools/testing/selftests/mm/.gitignore
index 7e2a982383c0..cdc9ce4426b9 100644
--- a/tools/testing/selftests/mm/.gitignore
+++ b/tools/testing/selftests/mm/.gitignore
@@ -5,6 +5,7 @@ hugepage-mremap
hugepage-shm
hugepage-vmemmap
hugetlb-madvise
+hugetlb-read-hwpoison
khugepaged
map_hugetlb
map_populate
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 66d7c07dc177..b7fce9073279 100644
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -41,6 +41,7 @@ TEST_GEN_PROGS += gup_longterm
TEST_GEN_PROGS += gup_test
TEST_GEN_PROGS += hmm-tests
TEST_GEN_PROGS += hugetlb-madvise
+TEST_GEN_PROGS += hugetlb-read-hwpoison
TEST_GEN_PROGS += hugepage-mmap
TEST_GEN_PROGS += hugepage-mremap
TEST_GEN_PROGS += hugepage-shm
diff --git a/tools/testing/selftests/mm/hugetlb-read-hwpoison.c b/tools/testing/selftests/mm/hugetlb-read-hwpoison.c
new file mode 100644
index 000000000000..ba6cc6f9cabc
--- /dev/null
+++ b/tools/testing/selftests/mm/hugetlb-read-hwpoison.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <linux/magic.h>
+#include <sys/mman.h>
+#include <sys/statfs.h>
+#include <errno.h>
+#include <stdbool.h>
+
+#include "../kselftest.h"
+
+#define PREFIX " ... "
+#define ERROR_PREFIX " !!! "
+
+#define MAX_WRITE_READ_CHUNK_SIZE (getpagesize() * 16)
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
+enum test_status {
+ TEST_PASSED = 0,
+ TEST_FAILED = 1,
+ TEST_SKIPPED = 2,
+};
+
+static char *status_to_str(enum test_status status)
+{
+ switch (status) {
+ case TEST_PASSED:
+ return "TEST_PASSED";
+ case TEST_FAILED:
+ return "TEST_FAILED";
+ case TEST_SKIPPED:
+ return "TEST_SKIPPED";
+ default:
+ return "TEST_???";
+ }
+}
+
+static int setup_filemap(char *filemap, size_t len, size_t wr_chunk_size)
+{
+ char iter = 0;
+
+ for (size_t offset = 0; offset < len;
+ offset += wr_chunk_size) {
+ iter++;
+ memset(filemap + offset, iter, wr_chunk_size);
+ }
+
+ return 0;
+}
+
+static bool verify_chunk(char *buf, size_t len, char val)
+{
+ size_t i;
+
+ for (i = 0; i < len; ++i) {
+ if (buf[i] != val) {
+ printf(PREFIX ERROR_PREFIX "check fail: buf[%lu] = %u != %u\n",
+ i, buf[i], val);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static bool seek_read_hugepage_filemap(int fd, size_t len, size_t wr_chunk_size,
+ off_t offset, size_t expected)
+{
+ char buf[MAX_WRITE_READ_CHUNK_SIZE];
+ ssize_t ret_count = 0;
+ ssize_t total_ret_count = 0;
+ char val = offset / wr_chunk_size + offset % wr_chunk_size;
+
+ printf(PREFIX PREFIX "init val=%u with offset=0x%lx\n", val, offset);
+ printf(PREFIX PREFIX "expect to read 0x%lx bytes of data in total\n",
+ expected);
+ if (lseek(fd, offset, SEEK_SET) < 0) {
+ perror(PREFIX ERROR_PREFIX "seek failed");
+ return false;
+ }
+
+ while (offset + total_ret_count < len) {
+ ret_count = read(fd, buf, wr_chunk_size);
+ if (ret_count == 0) {
+ printf(PREFIX PREFIX "read reach end of the file\n");
+ break;
+ } else if (ret_count < 0) {
+ perror(PREFIX ERROR_PREFIX "read failed");
+ break;
+ }
+ ++val;
+ if (!verify_chunk(buf, ret_count, val))
+ return false;
+
+ total_ret_count += ret_count;
+ }
+ printf(PREFIX PREFIX "actually read 0x%lx bytes of data in total\n",
+ total_ret_count);
+
+ return total_ret_count == expected;
+}
+
+static bool read_hugepage_filemap(int fd, size_t len,
+ size_t wr_chunk_size, size_t expected)
+{
+ char buf[MAX_WRITE_READ_CHUNK_SIZE];
+ ssize_t ret_count = 0;
+ ssize_t total_ret_count = 0;
+ char val = 0;
+
+ printf(PREFIX PREFIX "expect to read 0x%lx bytes of data in total\n",
+ expected);
+ while (total_ret_count < len) {
+ ret_count = read(fd, buf, wr_chunk_size);
+ if (ret_count == 0) {
+ printf(PREFIX PREFIX "read reach end of the file\n");
+ break;
+ } else if (ret_count < 0) {
+ perror(PREFIX ERROR_PREFIX "read failed");
+ break;
+ }
+ ++val;
+ if (!verify_chunk(buf, ret_count, val))
+ return false;
+
+ total_ret_count += ret_count;
+ }
+ printf(PREFIX PREFIX "actually read 0x%lx bytes of data in total\n",
+ total_ret_count);
+
+ return total_ret_count == expected;
+}
+
+static enum test_status
+test_hugetlb_read(int fd, size_t len, size_t wr_chunk_size)
+{
+ enum test_status status = TEST_SKIPPED;
+ char *filemap = NULL;
+
+ if (ftruncate(fd, len) < 0) {
+ perror(PREFIX ERROR_PREFIX "ftruncate failed");
+ return status;
+ }
+
+ filemap = mmap(NULL, len, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE, fd, 0);
+ if (filemap == MAP_FAILED) {
+ perror(PREFIX ERROR_PREFIX "mmap for primary mapping failed");
+ goto done;
+ }
+
+ setup_filemap(filemap, len, wr_chunk_size);
+ status = TEST_FAILED;
+
+ if (read_hugepage_filemap(fd, len, wr_chunk_size, len))
+ status = TEST_PASSED;
+
+ munmap(filemap, len);
+done:
+ if (ftruncate(fd, 0) < 0) {
+ perror(PREFIX ERROR_PREFIX "ftruncate back to 0 failed");
+ status = TEST_FAILED;
+ }
+
+ return status;
+}
+
+static enum test_status
+test_hugetlb_read_hwpoison(int fd, size_t len, size_t wr_chunk_size,
+ bool skip_hwpoison_page)
+{
+ enum test_status status = TEST_SKIPPED;
+ char *filemap = NULL;
+ char *hwp_addr = NULL;
+ const unsigned long pagesize = getpagesize();
+
+ if (ftruncate(fd, len) < 0) {
+ perror(PREFIX ERROR_PREFIX "ftruncate failed");
+ return status;
+ }
+
+ filemap = mmap(NULL, len, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE, fd, 0);
+ if (filemap == MAP_FAILED) {
+ perror(PREFIX ERROR_PREFIX "mmap for primary mapping failed");
+ goto done;
+ }
+
+ setup_filemap(filemap, len, wr_chunk_size);
+ status = TEST_FAILED;
+
+ /*
+ * Poisoned hugetlb page layout (assume hugepagesize=2MB):
+ * |<---------------------- 1MB ---------------------->|
+ * |<---- healthy page ---->|<---- HWPOISON page ----->|
+ * |<------------------- (1MB - 8KB) ----------------->|
+ */
+ hwp_addr = filemap + len / 2 + pagesize;
+ if (madvise(hwp_addr, pagesize, MADV_HWPOISON) < 0) {
+ perror(PREFIX ERROR_PREFIX "MADV_HWPOISON failed");
+ goto unmap;
+ }
+
+ if (!skip_hwpoison_page) {
+ /*
+ * Userspace should be able to read (1MB + 1 page) from
+ * the beginning of the HWPOISONed hugepage.
+ */
+ if (read_hugepage_filemap(fd, len, wr_chunk_size,
+ len / 2 + pagesize))
+ status = TEST_PASSED;
+ } else {
+ /*
+ * Userspace should be able to read (1MB - 2 pages) from
+ * HWPOISONed hugepage.
+ */
+ if (seek_read_hugepage_filemap(fd, len, wr_chunk_size,
+ len / 2 + MAX(2 * pagesize, wr_chunk_size),
+ len / 2 - MAX(2 * pagesize, wr_chunk_size)))
+ status = TEST_PASSED;
+ }
+
+unmap:
+ munmap(filemap, len);
+done:
+ if (ftruncate(fd, 0) < 0) {
+ perror(PREFIX ERROR_PREFIX "ftruncate back to 0 failed");
+ status = TEST_FAILED;
+ }
+
+ return status;
+}
+
+static int create_hugetlbfs_file(struct statfs *file_stat)
+{
+ int fd;
+
+ fd = memfd_create("hugetlb_tmp", MFD_HUGETLB);
+ if (fd < 0) {
+ perror(PREFIX ERROR_PREFIX "could not open hugetlbfs file");
+ return -1;
+ }
+
+ memset(file_stat, 0, sizeof(*file_stat));
+ if (fstatfs(fd, file_stat)) {
+ perror(PREFIX ERROR_PREFIX "fstatfs failed");
+ goto close;
+ }
+ if (file_stat->f_type != HUGETLBFS_MAGIC) {
+ printf(PREFIX ERROR_PREFIX "not hugetlbfs file\n");
+ goto close;
+ }
+
+ return fd;
+close:
+ close(fd);
+ return -1;
+}
+
+int main(void)
+{
+ int fd;
+ struct statfs file_stat;
+ enum test_status status;
+ /* Test read() in different granularity. */
+ size_t wr_chunk_sizes[] = {
+ getpagesize() / 2, getpagesize(),
+ getpagesize() * 2, getpagesize() * 4
+ };
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(wr_chunk_sizes); ++i) {
+ printf("Write/read chunk size=0x%lx\n",
+ wr_chunk_sizes[i]);
+
+ fd = create_hugetlbfs_file(&file_stat);
+ if (fd < 0)
+ goto create_failure;
+ printf(PREFIX "HugeTLB read regression test...\n");
+ status = test_hugetlb_read(fd, file_stat.f_bsize,
+ wr_chunk_sizes[i]);
+ printf(PREFIX "HugeTLB read regression test...%s\n",
+ status_to_str(status));
+ close(fd);
+ if (status == TEST_FAILED)
+ return -1;
+
+ fd = create_hugetlbfs_file(&file_stat);
+ if (fd < 0)
+ goto create_failure;
+ printf(PREFIX "HugeTLB read HWPOISON test...\n");
+ status = test_hugetlb_read_hwpoison(fd, file_stat.f_bsize,
+ wr_chunk_sizes[i], false);
+ printf(PREFIX "HugeTLB read HWPOISON test...%s\n",
+ status_to_str(status));
+ close(fd);
+ if (status == TEST_FAILED)
+ return -1;
+
+ fd = create_hugetlbfs_file(&file_stat);
+ if (fd < 0)
+ goto create_failure;
+ printf(PREFIX "HugeTLB seek then read HWPOISON test...\n");
+ status = test_hugetlb_read_hwpoison(fd, file_stat.f_bsize,
+ wr_chunk_sizes[i], true);
+ printf(PREFIX "HugeTLB seek then read HWPOISON test...%s\n",
+ status_to_str(status));
+ close(fd);
+ if (status == TEST_FAILED)
+ return -1;
+ }
+
+ return 0;
+
+create_failure:
+ printf(ERROR_PREFIX "Abort test: failed to create hugetlbfs file\n");
+ return -1;
+}
--
2.41.0.255.g8b1d071c50-goog
