On Mon, Mar 16, 2026 at 08:35:11AM +0200, Mike Rapoport wrote: > On Mon, Mar 16, 2026 at 12:43:33PM +0800, Chunyu Hu wrote: > > thp_settings provides write_file() helper for safely writing to a file and > > exit when write failure happens. It's a very low level helper and many sub > > tests need such a helper, not only thp tests. > > > > split_huge_page_test also defines a write_file locally. The two have minior > > differences in return type and used exit api. And there would be conflicts > > if split_huge_page_test wanted to include thp_settings.h because of > > different prototype, making it less convenient. > > > > It's possisble to merge the two, although some tests don't use the > > kselftest infrastrucutre for testing. It would also work when using the > > ksft_exit_msg() to exit in my test, as the counters are all zero. Output > > will be like: > > > > TAP version 13 > > 1..62 > > Bail out! /proc/sys/vm/drop_caches1 open failed: No such file or directory > > # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0 > > > > So here just leave one version of write_file, and move it into the vm_util. > > This make it easy to maitain and user could just include one vm_util.h when > > then don't need thp setting helpers. Keep the prototype of returning the > > written bytes num. > > > > Suggested-by: Mike Rapoport <[email protected]> > > Signed-off-by: Chunyu Hu <[email protected]> > > --- > > Changes in v2: > > new patch from v2 > > --- > > .../selftests/mm/split_huge_page_test.c | 15 ------------ > > tools/testing/selftests/mm/thp_settings.c | 24 +------------------ > > tools/testing/selftests/mm/thp_settings.h | 1 - > > tools/testing/selftests/mm/vm_util.c | 16 +++++++++++++ > > tools/testing/selftests/mm/vm_util.h | 2 ++ > > 5 files changed, 19 insertions(+), 39 deletions(-) > > > > diff --git a/tools/testing/selftests/mm/split_huge_page_test.c > > b/tools/testing/selftests/mm/split_huge_page_test.c > > index e0167111bdd1..93f205327b84 100644 > > --- a/tools/testing/selftests/mm/split_huge_page_test.c > > +++ b/tools/testing/selftests/mm/split_huge_page_test.c > > @@ -255,21 +255,6 @@ static int check_after_split_folio_orders(char > > *vaddr_start, size_t len, > > return status; > > } > > > > -static void write_file(const char *path, const char *buf, size_t buflen) > > -{ > > - int fd; > > - ssize_t numwritten; > > - > > - fd = open(path, O_WRONLY); > > - if (fd == -1) > > - ksft_exit_fail_msg("%s open failed: %s\n", path, > > strerror(errno)); > > - > > - numwritten = write(fd, buf, buflen - 1); > > - close(fd); > > - if (numwritten < 1) > > - ksft_exit_fail_msg("Write failed\n"); > > -} > > - > > static void write_debugfs(const char *fmt, ...) > > { > > char input[INPUT_MAX]; > > diff --git a/tools/testing/selftests/mm/thp_settings.c > > b/tools/testing/selftests/mm/thp_settings.c > > index 574bd0f8ae48..02de28ecf31a 100644 > > --- a/tools/testing/selftests/mm/thp_settings.c > > +++ b/tools/testing/selftests/mm/thp_settings.c > > @@ -6,6 +6,7 @@ > > #include <string.h> > > #include <unistd.h> > > > > +#include "vm_util.h" > > #include "thp_settings.h" > > > > #define THP_SYSFS "/sys/kernel/mm/transparent_hugepage/" > > @@ -64,29 +65,6 @@ int read_file(const char *path, char *buf, size_t buflen) > > return (unsigned int) numread; > > } > > > > -int write_file(const char *path, const char *buf, size_t buflen) > > -{ > > - int fd; > > - ssize_t numwritten; > > - > > - fd = open(path, O_WRONLY); > > - if (fd == -1) { > > - printf("open(%s)\n", path); > > - exit(EXIT_FAILURE); > > - return 0; > > - } > > - > > - numwritten = write(fd, buf, buflen - 1); > > - close(fd); > > - if (numwritten < 1) { > > - printf("write(%s)\n", buf); > > - exit(EXIT_FAILURE); > > - return 0; > > - } > > - > > - return (unsigned int) numwritten; > > -} > > - > > unsigned long read_num(const char *path) > > { > > char buf[21]; > > diff --git a/tools/testing/selftests/mm/thp_settings.h > > b/tools/testing/selftests/mm/thp_settings.h > > index 76eeb712e5f1..7748a9009191 100644 > > --- a/tools/testing/selftests/mm/thp_settings.h > > +++ b/tools/testing/selftests/mm/thp_settings.h > > @@ -63,7 +63,6 @@ struct thp_settings { > > }; > > > > int read_file(const char *path, char *buf, size_t buflen); > > -int write_file(const char *path, const char *buf, size_t buflen); > > unsigned long read_num(const char *path); > > void write_num(const char *path, unsigned long num); > > > > diff --git a/tools/testing/selftests/mm/vm_util.c > > b/tools/testing/selftests/mm/vm_util.c > > index a6d4ff7dfdc0..b4b3b48f8dc9 100644 > > --- a/tools/testing/selftests/mm/vm_util.c > > +++ b/tools/testing/selftests/mm/vm_util.c > > @@ -764,3 +764,19 @@ int unpoison_memory(unsigned long pfn) > > > > return ret > 0 ? 0 : -errno; > > } > > + > > +unsigned int write_file(const char *path, const char *buf, size_t buflen) > > +{ > > + int fd; > > + ssize_t numwritten; > > + > > + fd = open(path, O_WRONLY); > > + if (fd == -1) > > + ksft_exit_fail_msg("%s open failed: %s\n", path, > > strerror(errno)); > > + > > + numwritten = write(fd, buf, buflen - 1); > > + close(fd); > > + if (numwritten < 1) > > + ksft_exit_fail_msg("Write failed\n"); > > + return (unsigned int) numwritten; > > If we exit on any failure, the function can be void just like in > split_huge_page_test.c. This will also simplify write_num() and read_num() > in thp_settigns.c
Good point. I will change it to void. I wont touch read_file() here. > > > +} > > diff --git a/tools/testing/selftests/mm/vm_util.h > > b/tools/testing/selftests/mm/vm_util.h > > index e9c4e24769c1..22c8805e0d7a 100644 > > --- a/tools/testing/selftests/mm/vm_util.h > > +++ b/tools/testing/selftests/mm/vm_util.h > > @@ -166,3 +166,5 @@ int unpoison_memory(unsigned long pfn); > > > > #define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0) > > #define PAGEMAP_PFN(ent) ((ent) & ((1ull << 55) - 1)) > > + > > +unsigned int write_file(const char *path, const char *buf, size_t buflen); > > -- > > 2.53.0 > > > > -- > Sincerely yours, > Mike. >
