On Wed, Jun 01, 2022 at 02:09:50PM -0700, 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". Yes, when I was reading your other patch I was wishing no timeout of any of QE testbeds could trigger. If you plan to remove it anyway, mind to squash these? > > [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 1badb5d31bf9..aeee6f1ad8ef 100644 > --- a/tools/testing/selftests/vm/userfaultfd.c > +++ b/tools/testing/selftests/vm/userfaultfd.c > @@ -128,6 +128,8 @@ struct uffd_stats { > const char *examples = > "# Run anonymous memory test on 100MiB region with 99999 bounces:\n" > "./userfaultfd anon 100 99999\n\n" > + "# Run the same anonymous memory test, but using /dev/userfaultfd:\n" > + "./userfaultfd anon:dev 100 99999\n\n" > "# Run share memory test on 1GiB region with 99 bounces:\n" > "./userfaultfd shmem 1000 99\n\n" > "# Run hugetlb memory test on 256MiB region with 50 bounces:\n" > @@ -144,6 +146,13 @@ static void usage(void) > "[hugetlbfs_file]\n\n"); > fprintf(stderr, "Supported <test type>: anon, hugetlb, " > "hugetlb_shared, shmem\n\n"); > + 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"); That looks better than running everything by default twice. Though let's also provide "syscall" if we're at it, anyway? Thanks, > + 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); > exit(1); > @@ -1607,8 +1616,6 @@ 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; > @@ -1626,10 +1633,28 @@ 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); > + } > +} > + > +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 > @@ -1676,7 +1701,7 @@ 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 / > @@ -1714,12 +1739,6 @@ 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(); > } > > -- > 2.36.1.255.ge46751e96f-goog > -- Peter Xu
