Messages in this thread | | | Subject | Re: [PATCH v2 5/6] userfaultfd: selftests: make /dev/userfaultfd testing configurable | From | Shuah Khan <> | Date | Tue, 26 Apr 2022 10:56:38 -0600 |
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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@vmware.com/ > > Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> > --- > 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.
> 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.
> +} > + > +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.
thanks, -- Shuah
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