userfaultfd/selftests: only dump counts if mode enabled

WP and MINOR modes are conditionally enabled on specific memory types.
This patch avoids dumping tons of zeros for those cases when the modes are
not supported at all.

Link: https://lkml.kernel.org/r/20210412232753.1012412-5-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 387b9360ae64fdf594503a01f6460de5702dc9bd..da2374bda5a347c3e06a4dcb8ae3880edb3bb37c 100644 (file)
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -171,16 +171,26 @@ static void uffd_stats_report(struct uffd_stats *stats, int n_cpus)
                minor_total += stats[i].minor_faults;
        }
 
-       printf("userfaults: %llu missing (", miss_total);
-       for (i = 0; i < n_cpus; i++)
-               printf("%lu+", stats[i].missing_faults);
-       printf("\b), %llu wp (", wp_total);
-       for (i = 0; i < n_cpus; i++)
-               printf("%lu+", stats[i].wp_faults);
-       printf("\b), %llu minor (", minor_total);
-       for (i = 0; i < n_cpus; i++)
-               printf("%lu+", stats[i].minor_faults);
-       printf("\b)\n");
+       printf("userfaults: ");
+       if (miss_total) {
+               printf("%llu missing (", miss_total);
+               for (i = 0; i < n_cpus; i++)
+                       printf("%lu+", stats[i].missing_faults);
+               printf("\b) ");
+       }
+       if (wp_total) {
+               printf("%llu wp (", wp_total);
+               for (i = 0; i < n_cpus; i++)
+                       printf("%lu+", stats[i].wp_faults);
+               printf("\b) ");
+       }
+       if (minor_total) {
+               printf("%llu minor (", minor_total);
+               for (i = 0; i < n_cpus; i++)
+                       printf("%lu+", stats[i].minor_faults);
+               printf("\b)");
+       }
+       printf("\n");
 }
 
 static int anon_release_pages(char *rel_area)