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From:   Peter Xu <peterx@redhat.com>
To:     linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc:     Axel Rasmussen <axelrasmussen@google.com>,
        Andrew Morton <akpm@linux-foundation.org>, peterx@redhat.com,
        Andrea Arcangeli <aarcange@redhat.com>,
        Nadav Amit <nadav.amit@gmail.com>
Subject: [PATCH 4/5] userfaultfd/selftests: Only dump counts if mode enabled
Date:   Tue,  9 Mar 2021 19:45:10 -0500
Message-Id: <20210310004511.51996-5-peterx@redhat.com>
In-Reply-To: <20210310004511.51996-1-peterx@redhat.com>
References: <20210310004511.51996-1-peterx@redhat.com>
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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.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 tools/testing/selftests/vm/userfaultfd.c | 30 ++++++++++++++++--------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index cf0cd4cb327d..5f89d258024a 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -173,16 +173,26 @@ 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)
-- 
2.26.2