On Mon, May 25, 2026 at 11:59:32AM +0530, Sarthak Sharma wrote: > Hi Mike! > > On 5/24/26 10:36 PM, Mike Rapoport wrote: > > On Thu, 21 May 2026 16:47:58 +0530, Sarthak Sharma <[email protected]> > > wrote: > > > > Hi Sarthak, > > > >> > >> diff --git a/tools/lib/mm/file_utils.c b/tools/lib/mm/file_utils.c > >> new file mode 100644 > >> index 000000000000..0f9322f2cf41 > >> --- /dev/null > >> +++ b/tools/lib/mm/file_utils.c > >> @@ -0,0 +1,83 @@ > >> [ ... skip 48 lines ... ] > >> + saved_errno = errno; > >> + close(fd); > >> + errno = saved_errno; > >> + if (numwritten < 0) { > >> + fprintf(stderr, "%s write(%.*s) failed: %s\n", > >> + path, (int)(buflen - 1), buf, strerror(errno)); > > > > This would break TAP formatting for selftests. > > Yes, thanks for pointing it out. > > > > >> + exit(EXIT_FAILURE); > > > > and while EXIT_FAILURE == KSFT_FAIL I'm not sure it's robust enough. > > I used EXIT_FAILURE here because the helper is moving out of selftests > and should not include kselftest.h anymore. The helper already > terminated the process on these paths, so I tried to preserve that > behavior while removing the ksft dependency.
In mm selftests a failure to update a /proc or /sysfs file meant there is no point to continue the test. But if we make it a generic helper for potentially broader use than mm selftests, exit() on failure is too harsh. > We can change this to return errors instead of calling exit() and update > the selftest callers to report failures through the ksft_* helpers. I > agree this is cleaner, but it would grow the series a bit. > > If you feel strongly, I can include these changes in v4. Otherwise I > feel we can handle it separately later to avoid growing this series. There are not that many callers of write_file() and write_num(). I think a patch that makes them return an error rather than exit() can go before moving these functions to lib. > >> > >> diff --git a/tools/testing/selftests/mm/hugepage_settings.c > >> b/tools/testing/selftests/mm/hugepage_settings.c > >> index 2eab2110ac6a..5e947abb7425 100644 > >> --- a/tools/testing/selftests/mm/hugepage_settings.c > >> +++ b/tools/testing/selftests/mm/hugepage_settings.c > >> @@ -8,8 +8,9 @@ > >> #include <stdlib.h> > >> #include <string.h> > >> #include <unistd.h> > >> +#include <mm/file_utils.h> > >> > >> -#include "vm_util.h" > > > > I think it would be fine to include file_utils.h in vm_utils.h and avoid > > further churn. > > Okay, I'll change this. -- Sincerely yours, Mike.
