On 1/28/22 3:26 PM, Mike Kravetz wrote:
Now that MADV_DONTNEED support for hugetlb is enabled, add corresponding
tests. MADV_REMOVE has been enabled for some time, but no tests exist
so add them as well.
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
tools/testing/selftests/vm/Makefile | 1 +
tools/testing/selftests/vm/hugetlb-madvise.c | 401 +++++++++++++++++++
tools/testing/selftests/vm/run_vmtests.sh | 12 +
3 files changed, 414 insertions(+)
create mode 100644 tools/testing/selftests/vm/hugetlb-madvise.c
diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index 1607322a112c..f60cf43bbf61 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -28,6 +28,7 @@ LDLIBS = -lrt -lpthread
TEST_GEN_FILES = compaction_test
TEST_GEN_FILES += gup_test
TEST_GEN_FILES += hmm-tests
+TEST_GEN_FILES += hugetlb-madvise
Please update .gitignore with the new binary.
TEST_GEN_FILES += hugepage-mmap
TEST_GEN_FILES += hugepage-mremap
TEST_GEN_FILES += hugepage-shm
diff --git a/tools/testing/selftests/vm/hugetlb-madvise.c b/tools/testing/selftests/vm/hugetlb-madvise.c
new file mode 100644
index 000000000000..31c302528f2c
--- /dev/null
+++ b/tools/testing/selftests/vm/hugetlb-madvise.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * hugepage-madvise:
+ *
+ * Basic functional testing of madvise MADV_DONTNEED and MADV_REMOVE
+ * on hugetlb mappings.
+ *
+ * Before running this test, make sure the administrator has pre-allocated
+ * at least MIN_FREE_PAGES hugetlb pages and they are free. In addition,
+ * the test takes an argument that is the path to a file in a hugetlbfs
+ * filesystem. Therefore, a hugetlbfs filesystem must be mounted on some
+ * directory.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#define __USE_GNU
+#include <fcntl.h>
+
+#define USAGE "USAGE: %s <hugepagefile_name>\n"
+#define MIN_FREE_PAGES 20
+
+#define validate_free_pages(exp_free) \
+ do { \
+ int fhp = get_free_hugepages(); \
+ if (fhp != (exp_free)) { \
+ printf("Unexpected number of free huge " \
+ "pages line %d\n", __LINE__); \
+ exit(1); \
+ } \
+ } while (0)
+
+unsigned long huge_page_size;
+unsigned long base_page_size;
+
+/*
+ * default_huge_page_size copied from mlock2-tests.c
+ */
+unsigned long default_huge_page_size(void)
+{
+ unsigned long hps = 0;
+ char *line = NULL;
+ size_t linelen = 0;
+ FILE *f = fopen("/proc/meminfo", "r");
+
+ if (!f)
+ return 0;
+ while (getline(&line, &linelen, f) > 0) {
+ if (sscanf(line, "Hugepagesize: %lu kB", &hps) == 1) {
+ hps <<= 10;
+ break;
+ }
+ }
+
+ free(line);
+ fclose(f);
+ return hps;
+}
+
+unsigned long get_free_hugepages(void)
+{
+ unsigned long fhp = 0;
+ char *line = NULL;
+ size_t linelen = 0;
+ FILE *f = fopen("/proc/meminfo", "r");
+
+ if (!f)
+ return fhp;
+ while (getline(&line, &linelen, f) > 0) {
+ if (sscanf(line, "HugePages_Free: %lu", &fhp) == 1)
+ break;
+ }
+
+ free(line);
+ fclose(f);
+ return fhp;
+}
+
+void write_fault_pages(void *addr, unsigned long nr_pages)
+{
+ unsigned long i;
+
+ for (i = 0; i < nr_pages; i++)
+ *((unsigned long *)(addr + (i * huge_page_size))) = i;
+}
+
+void read_fault_pages(void *addr, unsigned long nr_pages)
+{
+ unsigned long i, tmp;
+
+ for (i = 0; i < nr_pages; i++)
+ tmp += *((unsigned long *)(addr + (i * huge_page_size)));
+}
+
+int main(int argc, char **argv)
+{
+ unsigned long free_hugepages;
+ void *addr, *addr2;
+ int fd;
+ int ret;
+
+ if (argc != 2) {
+ printf(USAGE, argv[0]);
+ exit(1);
+ }
+
+ huge_page_size = default_huge_page_size();
+ if (!huge_page_size) {
+ printf("Unable to determine huge page size, exiting!\n");
+ exit(1);
+ }
+ base_page_size = sysconf(_SC_PAGE_SIZE);
+ if (!huge_page_size) {
+ printf("Unable to determine base page size, exiting!\n");
+ exit(1);
+ }
+
+ free_hugepages = get_free_hugepages();
+ if (free_hugepages < MIN_FREE_PAGES) {
+ printf("Not enough free huge pages to test, exiting!\n");
+ exit(1);
+ }
+
+ fd = open(argv[1], O_CREAT | O_RDWR, 0755);
+ if (fd < 0) {
+ perror("Open failed");
+ exit(1);
+ }
+
+ /*
+ * Test validity of MADV_DONTNEED addr and length arguments
+ */
+ addr = mmap(NULL, 12 * huge_page_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
+ -1, 0);
What is 12 here? Any significance to this value? Add a define for it
so it it clear why it is used.
+ if (addr == MAP_FAILED) {
+ perror("mmap");
+ exit(1);
+ }
+ /* unmap first and last page so we know nothing is mapped there */
+ if (munmap(addr, huge_page_size) ||
+ munmap(addr + 11 * huge_page_size, huge_page_size)) {
+ perror("munmap");
+ exit(1);
+ }
+ addr = addr + huge_page_size;
+
+ write_fault_pages(addr, 10);
What is 10 here? Any significance to this value? Add a define for it
so it it clear why it is used.
+ validate_free_pages(free_hugepages - 10);
+
+ /* addr before mapping should fail */
+ ret = madvise(addr - base_page_size, 10 * huge_page_size,
+ MADV_DONTNEED);
+ if (!ret) {
+ printf("Unexpected success of madvise call with invalid addr line %d\n",
+ __LINE__);
+ exit(1);
+ }
+
+ /* addr + length after mapping should fail */
+ ret = madvise(addr, (10 * huge_page_size) + base_page_size,
+ MADV_DONTNEED);
+ if (!ret) {
+ printf("Unexpected success of madvise call with invalid length line %d\n",
+ __LINE__);
+ exit(1);
+ }
+
+ (void)munmap(addr, 10 * huge_page_size);
Same comment on use of 10.
+
+ /*
+ * Test alignment of MADV_DONTNEED addr and length arguments
+ */
+ addr = mmap(NULL, 10 * huge_page_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
+ -1, 0);
+ if (addr == MAP_FAILED) {
+ perror("mmap");
+ exit(1);
+ }
+ write_fault_pages(addr, 10);
Ditto
+ validate_free_pages(free_hugepages - 10);
Ditto
+
+ /* addr should be aligned down to huge page size */
+ if (madvise(addr + base_page_size,
+ 10 * huge_page_size - base_page_size, MADV_DONTNEED)) {
+ perror("madvise");
+ exit(1);
+ }
+
+ /* should free all pages in mapping */
+ validate_free_pages(free_hugepages);
+
+ write_fault_pages(addr, 10);
+ validate_free_pages(free_hugepages - 10);
+
+ /* addr + length should be aligned up to huge page size */
+ if (madvise(addr, (10 * huge_page_size) - base_page_size,
+ MADV_DONTNEED)) {
+ perror("madvise");
+ exit(1);
+ }
+
+ /* should free all pages in mapping */
+ validate_free_pages(free_hugepages);
+
+ (void)munmap(addr, 10 * huge_page_size);
+
+ /*
+ * Test MADV_DONTNEED on anonymous private mapping
+ */
+ addr = mmap(NULL, 10 * huge_page_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
+ -1, 0);
+ if (addr == MAP_FAILED) {
+ perror("mmap");
+ exit(1);
+ }
+ write_fault_pages(addr, 10);
+ validate_free_pages(free_hugepages - 10);
+
+ if (madvise(addr, 10 * huge_page_size, MADV_DONTNEED)) {
+ perror("madvise");
+ exit(1);
+ }
+
+ /* should free all pages in mapping */
+ validate_free_pages(free_hugepages);
+
+ (void)munmap(addr, 10 * huge_page_size);
+
+ /*
+ * Test MADV_DONTNEED on private mapping of hugetlb file
+ */
+ if (fallocate(fd, 0, 0, 10 * huge_page_size)) {
+ perror("fallocate");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages - 10);
+
+ addr = mmap(NULL, 10 * huge_page_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE, fd, 0);
+ if (addr == MAP_FAILED) {
+ perror("mmap");
+ exit(1);
+ }
+
+ /* read should not consume any pages */
+ read_fault_pages(addr, 10);
+ validate_free_pages(free_hugepages - 10);
+
+ /* madvise should not free any pages */
+ if (madvise(addr, 10 * huge_page_size, MADV_DONTNEED)) {
+ perror("madvise");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages - 10);
+
+ /* writes should allocate private pages */
+ write_fault_pages(addr, 10);
+ validate_free_pages(free_hugepages - 20);
+
+ /* madvise should free private pages */
+ if (madvise(addr, 10 * huge_page_size, MADV_DONTNEED)) {
+ perror("madvise");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages - 10);
+
+ /* writes should allocate private pages */
+ write_fault_pages(addr, 10);
+ validate_free_pages(free_hugepages - 20);
+
+ /*
+ * The fallocate below certainly should free the pages associated
+ * with the file. However, pages in the private mapping are also
+ * freed. This is not the 'correct' behavior, but is expected
+ * because this is how it has worked since the initial hugetlb
+ * implementation.
+ */
+ if (fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ 0, 10 * huge_page_size)) {
+ perror("fallocate");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages);
+
+ (void)munmap(addr, 10 * huge_page_size);
+
+ /*
+ * Test MADV_DONTNEED on shared mapping of hugetlb file
+ */
+ if (fallocate(fd, 0, 0, 10 * huge_page_size)) {
+ perror("fallocate");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages - 10);
+
+ addr = mmap(NULL, 10 * huge_page_size, PROT_READ | PROT_WRITE,
+ MAP_SHARED, fd, 0);
+ if (addr == MAP_FAILED) {
+ perror("mmap");
+ exit(1);
+ }
+
+ /* write should not consume any pages */
+ write_fault_pages(addr, 10);
+ validate_free_pages(free_hugepages - 10);
+
+ /* madvise should not free any pages */
+ if (madvise(addr, 10 * huge_page_size, MADV_DONTNEED)) {
+ perror("madvise");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages - 10);
+
+ /*
+ * Test MADV_REMOVE on shared mapping of hugetlb file
+ *
+ * madvise is same as hole punch and should free all pages.
+ */
+ if (madvise(addr, 10 * huge_page_size, MADV_REMOVE)) {
+ perror("madvise");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages);
+ (void)munmap(addr, 10 * huge_page_size);
+
+ /*
+ * Test MADV_REMOVE on shared and private mapping of hugetlb file
+ */
+ if (fallocate(fd, 0, 0, 10 * huge_page_size)) {
+ perror("fallocate");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages - 10);
+
+ addr = mmap(NULL, 10 * huge_page_size, PROT_READ | PROT_WRITE,
+ MAP_SHARED, fd, 0);
+ if (addr == MAP_FAILED) {
+ perror("mmap");
+ exit(1);
+ }
+
+ /* shared write should not consume any additional pages */
+ write_fault_pages(addr, 10);
+ validate_free_pages(free_hugepages - 10);
+
+ addr2 = mmap(NULL, 10 * huge_page_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE, fd, 0);
+ if (addr2 == MAP_FAILED) {
+ perror("mmap");
+ exit(1);
+ }
+
+ /* private read should not consume any pages */
+ read_fault_pages(addr2, 10);
+ validate_free_pages(free_hugepages - 10);
+
+ /* private write should consume additional pages */
+ write_fault_pages(addr2, 10);
+ validate_free_pages(free_hugepages - 20);
+
+ /* madvise of shared mapping should not free any pages */
+ if (madvise(addr, 10 * huge_page_size, MADV_DONTNEED)) {
+ perror("madvise");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages - 20);
+
+ /* madvise of private mapping should free private pages */
+ if (madvise(addr2, 10 * huge_page_size, MADV_DONTNEED)) {
+ perror("madvise");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages - 10);
+
+ /* private write should consume additional pages again */
+ write_fault_pages(addr2, 10);
+ validate_free_pages(free_hugepages - 20);
+
+ /*
+ * madvise should free both file and private pages although this is
+ * not correct. private pages should not be freed, but this is
+ * expected. See comment associated with FALLOC_FL_PUNCH_HOLE call.
+ */
+ if (madvise(addr, 10 * huge_page_size, MADV_REMOVE)) {
+ perror("madvise");
+ exit(1);
+ }
+ validate_free_pages(free_hugepages);
+
+ (void)munmap(addr, 10 * huge_page_size);
+ (void)munmap(addr2, 10 * huge_page_size);
+
+ close(fd);
+ unlink(argv[1]);
+ return 0;
+}
Same comment on all usages of value 10
diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh
index 75d401741394..e0daf9ff0cbe 100755
--- a/tools/testing/selftests/vm/run_vmtests.sh
+++ b/tools/testing/selftests/vm/run_vmtests.sh
@@ -119,6 +119,18 @@ else
echo "[PASS]"
fi
+echo "-----------------------"
+echo "running hugetlb-madvise"
+echo "-----------------------"
+./hugetlb-madvise $mnt/madvise-test
+if [ $? -ne 0 ]; then
+ echo "[FAIL]"
+ exitcode=1
+else
+ echo "[PASS]"
+fi
+rm -f $mnt/madvise-test
+
echo "NOTE: The above hugetlb tests provide minimal coverage. Use"
echo " https://github.com/libhugetlbfs/libhugetlbfs.git for"
echo " hugetlb regression testing."
With these comments addressed/explained
Reviewed-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
thanks,
-- Shuah
