From: Alexander Zhu <alexlzhu@fb.com>
Self tests to verify the RssAnon value to make sure zero
pages are not remapped except in the case of userfaultfd.
Also includes a self test for the userfaultfd use case.
Signed-off-by: Alexander Zhu <alexlzhu@fb.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
---
.../selftests/mm/split_huge_page_test.c | 113 ++++++++++++++++++
tools/testing/selftests/mm/vm_util.c | 22 ++++
tools/testing/selftests/mm/vm_util.h | 1 +
3 files changed, 136 insertions(+)
diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c
index e5e8dafc9d94..da271ad6ff11 100644
--- a/tools/testing/selftests/mm/split_huge_page_test.c
+++ b/tools/testing/selftests/mm/split_huge_page_test.c
@@ -17,6 +17,8 @@
#include <malloc.h>
#include <stdbool.h>
#include <time.h>
+#include <sys/syscall.h>
+#include <linux/userfaultfd.h>
#include "vm_util.h"
#include "../kselftest.h"
@@ -84,6 +86,115 @@ static void write_debugfs(const char *fmt, ...)
write_file(SPLIT_DEBUGFS, input, ret + 1);
}
+static char *allocate_zero_filled_hugepage(size_t len)
+{
+ char *result;
+ size_t i;
+
+ result = memalign(pmd_pagesize, len);
+ if (!result) {
+ printf("Fail to allocate memory\n");
+ exit(EXIT_FAILURE);
+ }
+
+ madvise(result, len, MADV_HUGEPAGE);
+
+ for (i = 0; i < len; i++)
+ result[i] = (char)0;
+
+ return result;
+}
+
+static void verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int nr_hpages, size_t len)
+{
+ uint64_t rss_anon_before, rss_anon_after;
+ size_t i;
+
+ if (!check_huge_anon(one_page, 4, pmd_pagesize)) {
+ printf("No THP is allocated\n");
+ exit(EXIT_FAILURE);
+ }
+
+ rss_anon_before = rss_anon();
+ if (!rss_anon_before) {
+ printf("No RssAnon is allocated before split\n");
+ exit(EXIT_FAILURE);
+ }
+
+ /* split all THPs */
+ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page,
+ (uint64_t)one_page + len, 0);
+
+ for (i = 0; i < len; i++)
+ if (one_page[i] != (char)0) {
+ printf("%ld byte corrupted\n", i);
+ exit(EXIT_FAILURE);
+ }
+
+ if (!check_huge_anon(one_page, 0, pmd_pagesize)) {
+ printf("Still AnonHugePages not split\n");
+ exit(EXIT_FAILURE);
+ }
+
+ rss_anon_after = rss_anon();
+ if (rss_anon_after >= rss_anon_before) {
+ printf("Incorrect RssAnon value. Before: %ld After: %ld\n",
+ rss_anon_before, rss_anon_after);
+ exit(EXIT_FAILURE);
+ }
+}
+
+void split_pmd_zero_pages(void)
+{
+ char *one_page;
+ int nr_hpages = 4;
+ size_t len = nr_hpages * pmd_pagesize;
+
+ one_page = allocate_zero_filled_hugepage(len);
+ verify_rss_anon_split_huge_page_all_zeroes(one_page, nr_hpages, len);
+ printf("Split zero filled huge pages successful\n");
+ free(one_page);
+}
+
+void split_pmd_zero_pages_uffd(void)
+{
+ char *one_page;
+ int nr_hpages = 4;
+ size_t len = nr_hpages * pmd_pagesize;
+ long uffd; /* userfaultfd file descriptor */
+ struct uffdio_api uffdio_api;
+ struct uffdio_register uffdio_register;
+
+ /* Create and enable userfaultfd object. */
+
+ uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
+ if (uffd == -1) {
+ perror("userfaultfd");
+ exit(1);
+ }
+
+ uffdio_api.api = UFFD_API;
+ uffdio_api.features = 0;
+ if (ioctl(uffd, UFFDIO_API, &uffdio_api) == -1) {
+ perror("ioctl-UFFDIO_API");
+ exit(1);
+ }
+
+ one_page = allocate_zero_filled_hugepage(len);
+
+ uffdio_register.range.start = (unsigned long)one_page;
+ uffdio_register.range.len = len;
+ uffdio_register.mode = UFFDIO_REGISTER_MODE_WP;
+ if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) {
+ perror("ioctl-UFFDIO_REGISTER");
+ exit(1);
+ }
+
+ verify_rss_anon_split_huge_page_all_zeroes(one_page, nr_hpages, len);
+ printf("Split zero filled huge pages with uffd successful\n");
+ free(one_page);
+}
+
void split_pmd_thp(void)
{
char *one_page;
@@ -431,6 +542,8 @@ int main(int argc, char **argv)
fd_size = 2 * pmd_pagesize;
+ split_pmd_zero_pages();
+ split_pmd_zero_pages_uffd();
split_pmd_thp();
split_pte_mapped_thp();
split_file_backed_thp();
diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index 5a62530da3b5..7b7e763ba8e3 100644
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -12,6 +12,7 @@
#define PMD_SIZE_FILE_PATH "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size"
#define SMAP_FILE_PATH "/proc/self/smaps"
+#define STATUS_FILE_PATH "/proc/self/status"
#define MAX_LINE_LENGTH 500
unsigned int __page_size;
@@ -171,6 +172,27 @@ uint64_t read_pmd_pagesize(void)
return strtoul(buf, NULL, 10);
}
+uint64_t rss_anon(void)
+{
+ uint64_t rss_anon = 0;
+ FILE *fp;
+ char buffer[MAX_LINE_LENGTH];
+
+ fp = fopen(STATUS_FILE_PATH, "r");
+ if (!fp)
+ ksft_exit_fail_msg("%s: Failed to open file %s\n", __func__, STATUS_FILE_PATH);
+
+ if (!check_for_pattern(fp, "RssAnon:", buffer, sizeof(buffer)))
+ goto err_out;
+
+ if (sscanf(buffer, "RssAnon:%10ld kB", &rss_anon) != 1)
+ ksft_exit_fail_msg("Reading status error\n");
+
+err_out:
+ fclose(fp);
+ return rss_anon;
+}
+
bool __check_huge(void *addr, char *pattern, int nr_hpages,
uint64_t hpage_size)
{
diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
index 9007c420d52c..71b75429f4a5 100644
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -39,6 +39,7 @@ unsigned long pagemap_get_pfn(int fd, char *start);
void clear_softdirty(void);
bool check_for_pattern(FILE *fp, const char *pattern, char *buf, size_t len);
uint64_t read_pmd_pagesize(void);
+uint64_t rss_anon(void);
bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size);
bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size);
bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size);
--
2.43.0Hi Usama,
kernel test robot noticed the following build warnings:
[auto build test WARNING on akpm-mm/mm-everything]
url: https://github.com/intel-lab-lkp/linux/commits/Usama-Arif/Revert-memcg-remove-mem_cgroup_uncharge_list/20240730-223949
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20240730125346.1580150-6-usamaarif642%40gmail.com
patch subject: [PATCH 5/6] mm: add selftests to split_huge_page() to verify unmap/zap of zero pages
:::::: branch date: 32 hours ago
:::::: commit date: 32 hours ago
compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240801/202408010618.lgnamdZd-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202408010618.lgnamdZd-lkp@intel.com/
All warnings (new ones prefixed by >>):
vm_util.c: In function 'rss_anon':
>> vm_util.c:188:41: warning: format '%ld' expects argument of type 'long int *', but argument 3 has type 'uint64_t *' {aka 'long long unsigned int *'} [-Wformat=]
188 | if (sscanf(buffer, "RssAnon:%10ld kB", &rss_anon) != 1)
| ~~~~^ ~~~~~~~~~
| | |
| | uint64_t * {aka long long unsigned int *}
| long int *
| %10lld
vim +188 tools/testing/selftests/mm/vm_util.c
642bc52aed9c99 tools/testing/selftests/vm/vm_util.c Muhammad Usama Anjum 2022-04-28 174
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 175 uint64_t rss_anon(void)
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 176 {
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 177 uint64_t rss_anon = 0;
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 178 FILE *fp;
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 179 char buffer[MAX_LINE_LENGTH];
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 180
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 181 fp = fopen(STATUS_FILE_PATH, "r");
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 182 if (!fp)
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 183 ksft_exit_fail_msg("%s: Failed to open file %s\n", __func__, STATUS_FILE_PATH);
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 184
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 185 if (!check_for_pattern(fp, "RssAnon:", buffer, sizeof(buffer)))
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 186 goto err_out;
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 187
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 @188 if (sscanf(buffer, "RssAnon:%10ld kB", &rss_anon) != 1)
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 189 ksft_exit_fail_msg("Reading status error\n");
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 190
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 191 err_out:
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 192 fclose(fp);
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 193 return rss_anon;
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 194 }
15bd39f288be91 tools/testing/selftests/mm/vm_util.c Alexander Zhu 2024-07-30 195
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On 01/08/2024 05:45, kernel test robot wrote:
> Hi Usama,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on akpm-mm/mm-everything]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Usama-Arif/Revert-memcg-remove-mem_cgroup_uncharge_list/20240730-223949
> base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link: https://lore.kernel.org/r/20240730125346.1580150-6-usamaarif642%40gmail.com
> patch subject: [PATCH 5/6] mm: add selftests to split_huge_page() to verify unmap/zap of zero pages
> :::::: branch date: 32 hours ago
> :::::: commit date: 32 hours ago
> compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240801/202408010618.lgnamdZd-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/r/202408010618.lgnamdZd-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
> vm_util.c: In function 'rss_anon':
>>> vm_util.c:188:41: warning: format '%ld' expects argument of type 'long int *', but argument 3 has type 'uint64_t *' {aka 'long long unsigned int *'} [-Wformat=]
> 188 | if (sscanf(buffer, "RssAnon:%10ld kB", &rss_anon) != 1)
> | ~~~~^ ~~~~~~~~~
> | | |
> | | uint64_t * {aka long long unsigned int *}
> | long int *
> | %10lld
>
>
Interesting affect of different compilers!
If I compile with the above suggestion on my machine, i.e. convert ld to lld, I get a warning on my machine that uint64_t is long unsigned int (and not long long unsigned int as above):
vm_util.c: In function ‘rss_anon’:
vm_util.c:188:42: warning: format ‘%lld’ expects argument of type ‘long long int *’, but argument 3 has type ‘uint64_t *’ {aka ‘long unsigned int *’} [-Wformat=]
188 | if (sscanf(buffer, "RssAnon:%10lld kB", &rss_anon) != 1)
| ~~~~~^ ~~~~~~~~~
| | |
| | uint64_t * {aka long unsigned int *}
| long long int *
| %10ld
I will just do below which should work hopefully with all compilers:
diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index 7b7e763ba8e3..bd147bdb1bb2 100644
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -172,9 +172,9 @@ uint64_t read_pmd_pagesize(void)
return strtoul(buf, NULL, 10);
}
-uint64_t rss_anon(void)
+long unsigned rss_anon(void)
{
- uint64_t rss_anon = 0;
+ long unsigned rss_anon = 0;
FILE *fp;
char buffer[MAX_LINE_LENGTH];
@@ -185,7 +185,7 @@ uint64_t rss_anon(void)
if (!check_for_pattern(fp, "RssAnon:", buffer, sizeof(buffer)))
goto err_out;
- if (sscanf(buffer, "RssAnon:%10ld kB", &rss_anon) != 1)
+ if (sscanf(buffer, "RssAnon:%10lu kB", &rss_anon) != 1)
ksft_exit_fail_msg("Reading status error\n");
err_out:
On Tue, 2024-07-30 at 13:46 +0100, Usama Arif wrote: > From: Alexander Zhu <alexlzhu@fb.com> > > Self tests to verify the RssAnon value to make sure zero > pages are not remapped except in the case of userfaultfd. > Also includes a self test for the userfaultfd use case. > > Signed-off-by: Alexander Zhu <alexlzhu@fb.com> > Signed-off-by: Usama Arif <usamaarif642@gmail.com> Acked-by: Rik van Riel <riel@surriel.com> -- All Rights Reversed.
© 2016 - 2026 Red Hat, Inc.