The patch titled
Subject: mm: huge_memory: debugfs for file-backed THP split.
has been removed from the -mm tree. Its filename was
mm-huge_memory-debugfs-for-file-backed-thp-split.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
From: Zi Yan <ziy@xxxxxxxxxx>
Subject: mm: huge_memory: debugfs for file-backed THP split.
Further extend <debugfs>/split_huge_pages to accept
"<path>,<off_start>,<off_end>" for file-backed THP split tests since tmpfs
may have file backed by THP that mapped nowhere.
Update selftest program to test file-backed THP split too.
Link: https://lkml.kernel.org/r/20210319005219.13595-2-zi.yan@xxxxxxxx
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Suggested-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reviewed-by: Yang Shi <shy828301@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Mika Penttila <mika.penttila@xxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Sandipan Das <sandipan@xxxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/split_huge_page_test.c | 79 +++++++++++-
1 file changed, 74 insertions(+), 5 deletions(-)
--- a/tools/testing/selftests/vm/split_huge_page_test.c~mm-huge_memory-debugfs-for-file-backed-thp-split
+++ a/tools/testing/selftests/vm/split_huge_page_test.c
@@ -7,11 +7,13 @@
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
+#include <stdarg.h>
#include <unistd.h>
#include <inttypes.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
+#include <sys/mount.h>
#include <malloc.h>
#include <stdbool.h>
@@ -24,6 +26,9 @@ uint64_t pmd_pagesize;
#define SMAP_PATH "/proc/self/smaps"
#define INPUT_MAX 80
+#define PID_FMT "%d,0x%lx,0x%lx"
+#define PATH_FMT "%s,0x%lx,0x%lx"
+
#define PFN_MASK ((1UL<<55)-1)
#define KPF_THP (1UL<<22)
@@ -87,13 +92,16 @@ static int write_file(const char *path,
return (unsigned int) numwritten;
}
-static void write_debugfs(int pid, uint64_t vaddr_start, uint64_t vaddr_end)
+static void write_debugfs(const char *fmt, ...)
{
char input[INPUT_MAX];
int ret;
+ va_list argp;
+
+ va_start(argp, fmt);
+ ret = vsnprintf(input, INPUT_MAX, fmt, argp);
+ va_end(argp);
- ret = snprintf(input, INPUT_MAX, "%d,0x%lx,0x%lx", pid, vaddr_start,
- vaddr_end);
if (ret >= INPUT_MAX) {
printf("%s: Debugfs input is too long\n", __func__);
exit(EXIT_FAILURE);
@@ -183,7 +191,8 @@ void split_pmd_thp(void)
}
/* split all THPs */
- write_debugfs(getpid(), (uint64_t)one_page, (uint64_t)one_page + len);
+ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page,
+ (uint64_t)one_page + len);
for (i = 0; i < len; i++)
if (one_page[i] != (char)i) {
@@ -274,7 +283,7 @@ void split_pte_mapped_thp(void)
}
/* split all remapped THPs */
- write_debugfs(getpid(), (uint64_t)pte_mapped,
+ write_debugfs(PID_FMT, getpid(), (uint64_t)pte_mapped,
(uint64_t)pte_mapped + pagesize * 4);
/* smap does not show THPs after mremap, use kpageflags instead */
@@ -300,6 +309,65 @@ void split_pte_mapped_thp(void)
close(kpageflags_fd);
}
+void split_file_backed_thp(void)
+{
+ int status;
+ int fd;
+ ssize_t num_written;
+ char tmpfs_template[] = "/tmp/thp_split_XXXXXX";
+ const char *tmpfs_loc = mkdtemp(tmpfs_template);
+ char testfile[INPUT_MAX];
+
+ status = mount("tmpfs", tmpfs_loc, "tmpfs", 0, "huge=always,size=4m");
+
+ if (status) {
+ printf("Unable to create a tmpfs for testing\n");
+ exit(EXIT_FAILURE);
+ }
+
+ status = snprintf(testfile, INPUT_MAX, "%s/thp_file", tmpfs_loc);
+ if (status >= INPUT_MAX) {
+ printf("Fail to create file-backed THP split testing file\n");
+ goto cleanup;
+ }
+
+ fd = open(testfile, O_CREAT|O_WRONLY);
+ if (fd == -1) {
+ perror("Cannot open testing file\n");
+ goto cleanup;
+ }
+
+ /* write something to the file, so a file-backed THP can be allocated */
+ num_written = write(fd, tmpfs_loc, sizeof(tmpfs_loc));
+ close(fd);
+
+ if (num_written < 1) {
+ printf("Fail to write data to testing file\n");
+ goto cleanup;
+ }
+
+ /* split the file-backed THP */
+ write_debugfs(PATH_FMT, testfile, 0, 1024);
+
+ status = unlink(testfile);
+ if (status)
+ perror("Cannot remove testing file\n");
+
+cleanup:
+ status = umount(tmpfs_loc);
+ if (status) {
+ printf("Unable to umount %s\n", tmpfs_loc);
+ exit(EXIT_FAILURE);
+ }
+ status = rmdir(tmpfs_loc);
+ if (status) {
+ perror("cannot remove tmp dir");
+ exit(EXIT_FAILURE);
+ }
+
+ printf("file-backed THP split test done, please check dmesg for more information\n");
+}
+
int main(int argc, char **argv)
{
if (geteuid() != 0) {
@@ -313,6 +381,7 @@ int main(int argc, char **argv)
split_pmd_thp();
split_pte_mapped_thp();
+ split_file_backed_thp();
return 0;
}
_
Patches currently in -mm which might be from ziy@xxxxxxxxxx are
