Messages in this thread | | | Date | Thu, 17 Aug 2023 12:01:58 -0600 | Subject | Re: [PATCH 3/3] selftests: cachestat: test for cachestat availability | From | Shuah Khan <> |
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On 8/17/23 08:47, Andre Przywara wrote: > On Wed, 16 Aug 2023 11:11:49 -0600 > Shuah Khan <skhan@linuxfoundation.org> wrote: > > Hi, > >> On 8/15/23 09:56, Andre Przywara wrote: >>> As cachestat is a new syscall, it won't be available on older kernels, >>> for instance those running on a build machine. In this case, a run >>> reports all tests as "not ok" at the moment. >>> >>> Test for the cachestat syscall availability first, before doing further >>> tests, and bail out early with a TAP SKIP comment. >>> >>> This also uses the opportunity to add the proper TAP headers, and add >>> one check for the syscall error handling (illegal file descriptor). >>> >>> Signed-off-by: Andre Przywara <andre.przywara@arm.com> >>> --- >>> .../selftests/cachestat/test_cachestat.c | 22 ++++++++++++++++++- >>> 1 file changed, 21 insertions(+), 1 deletion(-) >>> >>> diff --git a/tools/testing/selftests/cachestat/test_cachestat.c b/tools/testing/selftests/cachestat/test_cachestat.c >>> index a5a4ac8dcb76c..77620e7ecf562 100644 >>> --- a/tools/testing/selftests/cachestat/test_cachestat.c >>> +++ b/tools/testing/selftests/cachestat/test_cachestat.c >>> @@ -15,6 +15,8 @@ >>> >>> #include "../kselftest.h" >>> >>> +#define NR_TESTS 8 >>> + >>> static const char * const dev_files[] = { >>> "/dev/zero", "/dev/null", "/dev/urandom", >>> "/proc/version", "/proc" >>> @@ -235,7 +237,25 @@ bool test_cachestat_shmem(void) >>> >>> int main(void) >>> { >>> - int ret = 0; >>> + int ret; >>> + >>> + ksft_print_header(); >>> + >>> + ret = syscall(__NR_cachestat, -1, NULL, NULL, 0); >>> + if (ret == -1 && errno == ENOSYS) { >>> + printf("1..0 # Skipped: cachestat syscall not available\n"); >>> + return KSFT_SKIP; >> What happens when other errors besides ENOSYS? The test shouldn't >> continue. > > -1 is an illegal file descriptor, and this is checked below (still using > the same ret and errno), but reported using the normal framework. > This check above is done early, before we even announce the plan, so that > we can skip *all* of the tests, since they don't make any sense when the > syscall is not available at all. > > Does that make sense? >
Yup. I will apply this for Linux 6.6-rc1. You will get patchbot notification shortly.
thanks, -- Shuah
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