diff mbox series

[v6,3/4] selftest/mm: test enable_soft_offline behaviors

Message ID 20240626050818.2277273-4-jiaqiyan@google.com (mailing list archive)
State New
Headers show
Series Userspace controls soft-offline pages | expand

Commit Message

Jiaqi Yan June 26, 2024, 5:08 a.m. UTC 
Add regression and new tests when hugepage has correctable memory
errors, and how userspace wants to deal with it:
* if enable_soft_offline=1, mapped hugepage is soft offlined
* if enable_soft_offline=0, mapped hugepage is intact

Free hugepages case is not explicitly covered by the tests.

Hugepage having corrected memory errors is emulated with
MADV_SOFT_OFFLINE.

Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
---
 tools/testing/selftests/mm/.gitignore         |   1 +
 tools/testing/selftests/mm/Makefile           |   1 +
 .../selftests/mm/hugetlb-soft-offline.c       | 228 ++++++++++++++++++
 tools/testing/selftests/mm/run_vmtests.sh     |   4 +
 4 files changed, 234 insertions(+)
 create mode 100644 tools/testing/selftests/mm/hugetlb-soft-offline.c

Comments

Miaohe Lin June 28, 2024, 3:29 a.m. UTC | #1 
On 2024/6/26 13:08, Jiaqi Yan wrote:
> Add regression and new tests when hugepage has correctable memory
> errors, and how userspace wants to deal with it:
> * if enable_soft_offline=1, mapped hugepage is soft offlined
> * if enable_soft_offline=0, mapped hugepage is intact
> 
> Free hugepages case is not explicitly covered by the tests.
> 
> Hugepage having corrected memory errors is emulated with
> MADV_SOFT_OFFLINE.

Thanks for update.

> 
> Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
> ---
>  tools/testing/selftests/mm/.gitignore         |   1 +
>  tools/testing/selftests/mm/Makefile           |   1 +
>  .../selftests/mm/hugetlb-soft-offline.c       | 228 ++++++++++++++++++
>  tools/testing/selftests/mm/run_vmtests.sh     |   4 +
>  4 files changed, 234 insertions(+)
>  create mode 100644 tools/testing/selftests/mm/hugetlb-soft-offline.c
...
> +static void test_soft_offline_common(int enable_soft_offline)
> +{
> +	int fd;
> +	int expect_errno = enable_soft_offline ? 0 : EOPNOTSUPP;
> +	struct statfs file_stat;
> +	unsigned long hugepagesize_kb = 0;
> +	unsigned long nr_hugepages_before = 0;
> +	unsigned long nr_hugepages_after = 0;
> +	int ret;
> +
> +	ksft_print_msg("Test soft-offline when enabled_soft_offline=%d\n",
> +		       enable_soft_offline);
> +
> +	fd = create_hugetlbfs_file(&file_stat);
> +	if (fd < 0)
> +		ksft_exit_fail_msg("Failed to create hugetlbfs file\n");
> +
> +	hugepagesize_kb = file_stat.f_bsize / 1024;
> +	ksft_print_msg("Hugepagesize is %ldkB\n", hugepagesize_kb);
> +
> +	if (set_enable_soft_offline(enable_soft_offline)) {

Nit: should this be written as if (set_enable_soft_offline(enable_soft_offline) != 0) to keep consistent with below code?

> +		close(fd);
> +		ksft_exit_fail_msg("Failed to set enable_soft_offline\n");
> +	}
> +
> +	if (read_nr_hugepages(hugepagesize_kb, &nr_hugepages_before) != 0) {
> +		close(fd);
> +		ksft_exit_fail_msg("Failed to read nr_hugepages\n");
> +	}
> +
> +	ksft_print_msg("Before MADV_SOFT_OFFLINE nr_hugepages=%ld\n",
> +		       nr_hugepages_before);
> +
> +	ret = do_soft_offline(fd, 2 * file_stat.f_bsize, expect_errno);
> +
> +	if (read_nr_hugepages(hugepagesize_kb, &nr_hugepages_after) != 0) {
> +		close(fd);
> +		ksft_exit_fail_msg("Failed to read nr_hugepages\n");
> +	}
> +
...
> diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
> index 3157204b9047..781117fac1ba 100755
> --- a/tools/testing/selftests/mm/run_vmtests.sh
> +++ b/tools/testing/selftests/mm/run_vmtests.sh
> @@ -331,6 +331,10 @@ CATEGORY="hugetlb" run_test ./thuge-gen
>  CATEGORY="hugetlb" run_test ./charge_reserved_hugetlb.sh -cgroup-v2
>  CATEGORY="hugetlb" run_test ./hugetlb_reparenting_test.sh -cgroup-v2
>  if $RUN_DESTRUCTIVE; then
> +nr_hugepages_tmp=$(cat /proc/sys/vm/nr_hugepages)
> +echo 8 > /proc/sys/vm/nr_hugepages
> +CATEGORY="hugetlb" run_test ./hugetlb-soft-offline
> +echo "$nr_hugepages_tmp" > /proc/sys/vm/nr_hugepages

Should we save and restore the value of /proc/sys/vm/enable_soft_offline too?

With above fixed, this patch looks good to me.
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Thanks.
.
Jiaqi Yan June 28, 2024, 5:25 p.m. UTC | #2 
On Thu, Jun 27, 2024 at 8:29 PM Miaohe Lin <linmiaohe@huawei.com> wrote:
>
> On 2024/6/26 13:08, Jiaqi Yan wrote:
> > Add regression and new tests when hugepage has correctable memory
> > errors, and how userspace wants to deal with it:
> > * if enable_soft_offline=1, mapped hugepage is soft offlined
> > * if enable_soft_offline=0, mapped hugepage is intact
> >
> > Free hugepages case is not explicitly covered by the tests.
> >
> > Hugepage having corrected memory errors is emulated with
> > MADV_SOFT_OFFLINE.
>
> Thanks for update.
>
> >
> > Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
> > ---
> >  tools/testing/selftests/mm/.gitignore         |   1 +
> >  tools/testing/selftests/mm/Makefile           |   1 +
> >  .../selftests/mm/hugetlb-soft-offline.c       | 228 ++++++++++++++++++
> >  tools/testing/selftests/mm/run_vmtests.sh     |   4 +
> >  4 files changed, 234 insertions(+)
> >  create mode 100644 tools/testing/selftests/mm/hugetlb-soft-offline.c
> ...
> > +static void test_soft_offline_common(int enable_soft_offline)
> > +{
> > +     int fd;
> > +     int expect_errno = enable_soft_offline ? 0 : EOPNOTSUPP;
> > +     struct statfs file_stat;
> > +     unsigned long hugepagesize_kb = 0;
> > +     unsigned long nr_hugepages_before = 0;
> > +     unsigned long nr_hugepages_after = 0;
> > +     int ret;
> > +
> > +     ksft_print_msg("Test soft-offline when enabled_soft_offline=%d\n",
> > +                    enable_soft_offline);
> > +
> > +     fd = create_hugetlbfs_file(&file_stat);
> > +     if (fd < 0)
> > +             ksft_exit_fail_msg("Failed to create hugetlbfs file\n");
> > +
> > +     hugepagesize_kb = file_stat.f_bsize / 1024;
> > +     ksft_print_msg("Hugepagesize is %ldkB\n", hugepagesize_kb);
> > +
> > +     if (set_enable_soft_offline(enable_soft_offline)) {
>
> Nit: should this be written as if (set_enable_soft_offline(enable_soft_offline) != 0) to keep consistent with below code?

for sure

>
> > +             close(fd);
> > +             ksft_exit_fail_msg("Failed to set enable_soft_offline\n");
> > +     }
> > +
> > +     if (read_nr_hugepages(hugepagesize_kb, &nr_hugepages_before) != 0) {
> > +             close(fd);
> > +             ksft_exit_fail_msg("Failed to read nr_hugepages\n");
> > +     }
> > +
> > +     ksft_print_msg("Before MADV_SOFT_OFFLINE nr_hugepages=%ld\n",
> > +                    nr_hugepages_before);
> > +
> > +     ret = do_soft_offline(fd, 2 * file_stat.f_bsize, expect_errno);
> > +
> > +     if (read_nr_hugepages(hugepagesize_kb, &nr_hugepages_after) != 0) {
> > +             close(fd);
> > +             ksft_exit_fail_msg("Failed to read nr_hugepages\n");
> > +     }
> > +
> ...
> > diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
> > index 3157204b9047..781117fac1ba 100755
> > --- a/tools/testing/selftests/mm/run_vmtests.sh
> > +++ b/tools/testing/selftests/mm/run_vmtests.sh
> > @@ -331,6 +331,10 @@ CATEGORY="hugetlb" run_test ./thuge-gen
> >  CATEGORY="hugetlb" run_test ./charge_reserved_hugetlb.sh -cgroup-v2
> >  CATEGORY="hugetlb" run_test ./hugetlb_reparenting_test.sh -cgroup-v2
> >  if $RUN_DESTRUCTIVE; then
> > +nr_hugepages_tmp=$(cat /proc/sys/vm/nr_hugepages)
> > +echo 8 > /proc/sys/vm/nr_hugepages
> > +CATEGORY="hugetlb" run_test ./hugetlb-soft-offline
> > +echo "$nr_hugepages_tmp" > /proc/sys/vm/nr_hugepages
>
> Should we save and restore the value of /proc/sys/vm/enable_soft_offline too?

absolutely, thanks for catching.

>
> With above fixed, this patch looks good to me.
> Acked-by: Miaohe Lin <linmiaohe@huawei.com>

Thanks Miaohe, I will send out v7 with fixes.

> Thanks.
> .
>
diff mbox series

Patch

diff --git a/tools/testing/selftests/mm/.gitignore b/tools/testing/selftests/mm/.gitignore
index 0b9ab987601c..064e7b125643 100644
--- a/tools/testing/selftests/mm/.gitignore
+++ b/tools/testing/selftests/mm/.gitignore
@@ -6,6 +6,7 @@  hugepage-shm
 hugepage-vmemmap
 hugetlb-madvise
 hugetlb-read-hwpoison
+hugetlb-soft-offline
 khugepaged
 map_hugetlb
 map_populate
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 3b49bc3d0a3b..d166067d75ef 100644
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -42,6 +42,7 @@  TEST_GEN_FILES += gup_test
 TEST_GEN_FILES += hmm-tests
 TEST_GEN_FILES += hugetlb-madvise
 TEST_GEN_FILES += hugetlb-read-hwpoison
+TEST_GEN_FILES += hugetlb-soft-offline
 TEST_GEN_FILES += hugepage-mmap
 TEST_GEN_FILES += hugepage-mremap
 TEST_GEN_FILES += hugepage-shm
diff --git a/tools/testing/selftests/mm/hugetlb-soft-offline.c b/tools/testing/selftests/mm/hugetlb-soft-offline.c
new file mode 100644
index 000000000000..cde82705499b
--- /dev/null
+++ b/tools/testing/selftests/mm/hugetlb-soft-offline.c
@@ -0,0 +1,228 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test soft offline behavior for HugeTLB pages:
+ * - if enable_soft_offline = 0, hugepages should stay intact and soft
+ *   offlining failed with EOPNOTSUPP.
+ * - if enable_soft_offline = 1, a hugepage should be dissolved and
+ *   nr_hugepages/free_hugepages should be reduced by 1.
+ *
+ * Before running, make sure more than 2 hugepages of default_hugepagesz
+ * are allocated. For example, if /proc/meminfo/Hugepagesize is 2048kB:
+ *   echo 8 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <linux/magic.h>
+#include <linux/memfd.h>
+#include <sys/mman.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+
+#include "../kselftest.h"
+
+#ifndef MADV_SOFT_OFFLINE
+#define MADV_SOFT_OFFLINE 101
+#endif
+
+#define EPREFIX " !!! "
+
+static int do_soft_offline(int fd, size_t len, int expect_errno)
+{
+	char *filemap = NULL;
+	char *hwp_addr = NULL;
+	const unsigned long pagesize = getpagesize();
+	int ret = 0;
+
+	if (ftruncate(fd, len) < 0) {
+		ksft_perror(EPREFIX "ftruncate to len failed");
+		return -1;
+	}
+
+	filemap = mmap(NULL, len, PROT_READ | PROT_WRITE,
+		       MAP_SHARED | MAP_POPULATE, fd, 0);
+	if (filemap == MAP_FAILED) {
+		ksft_perror(EPREFIX "mmap failed");
+		ret = -1;
+		goto untruncate;
+	}
+
+	memset(filemap, 0xab, len);
+	ksft_print_msg("Allocated %#lx bytes of hugetlb pages\n", len);
+
+	hwp_addr = filemap + len / 2;
+	ret = madvise(hwp_addr, pagesize, MADV_SOFT_OFFLINE);
+	ksft_print_msg("MADV_SOFT_OFFLINE %p ret=%d, errno=%d\n",
+		       hwp_addr, ret, errno);
+	if (ret != 0)
+		ksft_perror(EPREFIX "madvise failed");
+
+	if (errno == expect_errno)
+		ret = 0;
+	else {
+		ksft_print_msg("MADV_SOFT_OFFLINE should ret %d\n",
+			       expect_errno);
+		ret = -1;
+	}
+
+	munmap(filemap, len);
+untruncate:
+	if (ftruncate(fd, 0) < 0)
+		ksft_perror(EPREFIX "ftruncate back to 0 failed");
+
+	return ret;
+}
+
+static int set_enable_soft_offline(int value)
+{
+	char cmd[256] = {0};
+	FILE *cmdfile = NULL;
+
+	if (value != 0 && value != 1)
+		return -EINVAL;
+
+	sprintf(cmd, "echo %d > /proc/sys/vm/enable_soft_offline", value);
+	cmdfile = popen(cmd, "r");
+
+	if (cmdfile)
+		ksft_print_msg("enable_soft_offline => %d\n", value);
+	else {
+		ksft_perror(EPREFIX "failed to set enable_soft_offline");
+		return errno;
+	}
+
+	pclose(cmdfile);
+	return 0;
+}
+
+static int read_nr_hugepages(unsigned long hugepage_size,
+			     unsigned long *nr_hugepages)
+{
+	char buffer[256] = {0};
+	char cmd[256] = {0};
+
+	sprintf(cmd, "cat /sys/kernel/mm/hugepages/hugepages-%ldkB/nr_hugepages",
+		hugepage_size);
+	FILE *cmdfile = popen(cmd, "r");
+
+	if (cmdfile == NULL) {
+		ksft_perror(EPREFIX "failed to popen nr_hugepages");
+		return -1;
+	}
+
+	if (!fgets(buffer, sizeof(buffer), cmdfile)) {
+		ksft_perror(EPREFIX "failed to read nr_hugepages");
+		pclose(cmdfile);
+		return -1;
+	}
+
+	*nr_hugepages = atoll(buffer);
+	pclose(cmdfile);
+	return 0;
+}
+
+static int create_hugetlbfs_file(struct statfs *file_stat)
+{
+	int fd;
+
+	fd = memfd_create("hugetlb_tmp", MFD_HUGETLB);
+	if (fd < 0) {
+		ksft_perror(EPREFIX "could not open hugetlbfs file");
+		return -1;
+	}
+
+	memset(file_stat, 0, sizeof(*file_stat));
+	if (fstatfs(fd, file_stat)) {
+		ksft_perror(EPREFIX "fstatfs failed");
+		goto close;
+	}
+	if (file_stat->f_type != HUGETLBFS_MAGIC) {
+		ksft_print_msg(EPREFIX "not hugetlbfs file\n");
+		goto close;
+	}
+
+	return fd;
+close:
+	close(fd);
+	return -1;
+}
+
+static void test_soft_offline_common(int enable_soft_offline)
+{
+	int fd;
+	int expect_errno = enable_soft_offline ? 0 : EOPNOTSUPP;
+	struct statfs file_stat;
+	unsigned long hugepagesize_kb = 0;
+	unsigned long nr_hugepages_before = 0;
+	unsigned long nr_hugepages_after = 0;
+	int ret;
+
+	ksft_print_msg("Test soft-offline when enabled_soft_offline=%d\n",
+		       enable_soft_offline);
+
+	fd = create_hugetlbfs_file(&file_stat);
+	if (fd < 0)
+		ksft_exit_fail_msg("Failed to create hugetlbfs file\n");
+
+	hugepagesize_kb = file_stat.f_bsize / 1024;
+	ksft_print_msg("Hugepagesize is %ldkB\n", hugepagesize_kb);
+
+	if (set_enable_soft_offline(enable_soft_offline)) {
+		close(fd);
+		ksft_exit_fail_msg("Failed to set enable_soft_offline\n");
+	}
+
+	if (read_nr_hugepages(hugepagesize_kb, &nr_hugepages_before) != 0) {
+		close(fd);
+		ksft_exit_fail_msg("Failed to read nr_hugepages\n");
+	}
+
+	ksft_print_msg("Before MADV_SOFT_OFFLINE nr_hugepages=%ld\n",
+		       nr_hugepages_before);
+
+	ret = do_soft_offline(fd, 2 * file_stat.f_bsize, expect_errno);
+
+	if (read_nr_hugepages(hugepagesize_kb, &nr_hugepages_after) != 0) {
+		close(fd);
+		ksft_exit_fail_msg("Failed to read nr_hugepages\n");
+	}
+
+	ksft_print_msg("After MADV_SOFT_OFFLINE nr_hugepages=%ld\n",
+		nr_hugepages_after);
+
+	// No need for the hugetlbfs file from now on.
+	close(fd);
+
+	if (enable_soft_offline) {
+		if (nr_hugepages_before != nr_hugepages_after + 1) {
+			ksft_test_result_fail("MADV_SOFT_OFFLINE should reduced 1 hugepage\n");
+			return;
+		}
+	} else {
+		if (nr_hugepages_before != nr_hugepages_after) {
+			ksft_test_result_fail("MADV_SOFT_OFFLINE reduced %lu hugepages\n",
+				nr_hugepages_before - nr_hugepages_after);
+			return;
+		}
+	}
+
+	ksft_test_result(ret == 0,
+			 "Test soft-offline when enabled_soft_offline=%d\n",
+			 enable_soft_offline);
+}
+
+int main(int argc, char **argv)
+{
+	ksft_print_header();
+	ksft_set_plan(2);
+
+	test_soft_offline_common(1);
+	test_soft_offline_common(0);
+
+	ksft_finished();
+}
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index 3157204b9047..781117fac1ba 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -331,6 +331,10 @@  CATEGORY="hugetlb" run_test ./thuge-gen
 CATEGORY="hugetlb" run_test ./charge_reserved_hugetlb.sh -cgroup-v2
 CATEGORY="hugetlb" run_test ./hugetlb_reparenting_test.sh -cgroup-v2
 if $RUN_DESTRUCTIVE; then
+nr_hugepages_tmp=$(cat /proc/sys/vm/nr_hugepages)
+echo 8 > /proc/sys/vm/nr_hugepages
+CATEGORY="hugetlb" run_test ./hugetlb-soft-offline
+echo "$nr_hugepages_tmp" > /proc/sys/vm/nr_hugepages
 CATEGORY="hugetlb" run_test ./hugetlb-read-hwpoison
 fi