On Tue, Apr 26, 2022 at 9:56 AM Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> wrote: > > On 4/22/22 3:29 PM, Axel Rasmussen wrote: > > Instead of always testing both userfaultfd(2) and /dev/userfaultfd, > > let the user choose which to test. > > > > As with other test features, change the behavior based on a new > > command line flag. Introduce the idea of "test mods", which are > > generic (not specific to a test type) modifications to the behavior of > > the test. This is sort of borrowed from this RFC patch series [1], but > > simplified a bit. > > > > The benefit is, in "typical" configurations this test is somewhat slow > > (say, 30sec or something). Testing both clearly doubles it, so it may > > not always be desirable, as users are likely to use one or the other, > > but never both, in the "real world". > > > > [1]: https://patchwork.kernel.org/project/linux-mm/patch/20201129004548.1619714-14-namit@xxxxxxxxxx/ > > > > Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> > > --- > > tools/testing/selftests/vm/userfaultfd.c | 41 +++++++++++++++++------- > > 1 file changed, 30 insertions(+), 11 deletions(-) > > > > diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c > > index 12ae742a9981..274522704e40 100644 > > --- a/tools/testing/selftests/vm/userfaultfd.c > > +++ b/tools/testing/selftests/vm/userfaultfd.c > > @@ -142,8 +142,17 @@ static void usage(void) > > { > > fprintf(stderr, "\nUsage: ./userfaultfd <test type> <MiB> <bounces> " > > "[hugetlbfs_file]\n\n"); > > + > > Remove the extra blank line here. > > > fprintf(stderr, "Supported <test type>: anon, hugetlb, " > > "hugetlb_shared, shmem\n\n"); > > + > > Remove the extra blank line here. > > > + fprintf(stderr, "'Test mods' can be joined to the test type string with a ':'. " > > + "Supported mods:\n"); > > + fprintf(stderr, "\tdev - Use /dev/userfaultfd instead of userfaultfd(2)\n"); > > + fprintf(stderr, "\nExample test mod usage:\n"); > > + fprintf(stderr, "# Run anonymous memory test with /dev/userfaultfd:\n"); > > + fprintf(stderr, "./userfaultfd anon:dev 100 99999\n\n"); > > + > > fprintf(stderr, "Examples:\n\n"); > > fprintf(stderr, "%s", examples); > > Update examples above with new test cases if any. Will fix the above comments in v3. > > > exit(1); > > @@ -1610,8 +1619,6 @@ unsigned long default_huge_page_size(void) > > > > static void set_test_type(const char *type) > > { > > - uint64_t features = UFFD_API_FEATURES; > > - > > if (!strcmp(type, "anon")) { > > test_type = TEST_ANON; > > uffd_test_ops = &anon_uffd_test_ops; > > @@ -1631,10 +1638,28 @@ static void set_test_type(const char *type) > > test_type = TEST_SHMEM; > > uffd_test_ops = &shmem_uffd_test_ops; > > test_uffdio_minor = true; > > - } else { > > - err("Unknown test type: %s", type); > > + } > > At this point, it might make it so much easier and maintainable if > we were to use getopt instead of parsing options. Agreed, I'd like that as well. But, since it's a bigger refactor that affects all test types, I think it may be cleaner to leave it for a follow-up series. > > > +} > > + > > +static void parse_test_type_arg(const char *raw_type) > > +{ > > + char *buf = strdup(raw_type); > > + uint64_t features = UFFD_API_FEATURES; > > + > > + while (buf) { > > + const char *token = strsep(&buf, ":"); > > + > > + if (!test_type) > > + set_test_type(token); > > + else if (!strcmp(token, "dev")) > > + test_dev_userfaultfd = true; > > + else > > + err("unrecognized test mod '%s'", token); > > } > > > > + if (!test_type) > > + err("failed to parse test type argument: '%s'", raw_type); > > + > > if (test_type == TEST_HUGETLB) > > page_size = default_huge_page_size(); > > else > > @@ -1681,7 +1706,7 @@ int main(int argc, char **argv) > > err("failed to arm SIGALRM"); > > alarm(ALARM_INTERVAL_SECS); > > > > - set_test_type(argv[1]); > > + parse_test_type_arg(argv[1]); > > > > nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); > > nr_pages_per_cpu = atol(argv[2]) * 1024*1024 / page_size / > > @@ -1719,12 +1744,6 @@ int main(int argc, char **argv) > > } > > printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n", > > nr_pages, nr_pages_per_cpu); > > - > > - test_dev_userfaultfd = false; > > - if (userfaultfd_stress()) > > - return 1; > > - > > - test_dev_userfaultfd = true; > > return userfaultfd_stress(); > > } > > > > > > Same comments as before on fail vs. skip conditions to watch out > for and report them correctly. I think in v3 things will be correct. Basically, in the skip cases we just exit(KSFT_SKIP) directly, instead of relying on the return value here. I'll take a pass and double check though before sending v3. > > thanks, > -- Shuah >
