From: Brendan Jackman <jackmanb@google.com>
Date: Fri, 21 Feb 2025 18:25:45 +0000 (+0000)
Subject: selftests/mm: print some details when uffd-stress gets bad params
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=55873c6c50e200974837c1b9f68e88ee02ad73e3;p=users%2Fjedix%2Flinux-maple.git

selftests/mm: print some details when uffd-stress gets bad params

So this can be debugged more easily.

Link: https://lkml.kernel.org/r/20250221-mm-selftests-v2-6-28c4d66383c5@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index 3d76386ab9c0..b28d39dbb2b2 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -457,7 +457,8 @@ int main(int argc, char **argv)
 
 	nr_pages_per_cpu = bytes / page_size / nr_threads;
 	if (!nr_pages_per_cpu) {
-		_err("invalid MiB");
+		_err("pages_per_cpu = 0, cannot test (%lu / %lu / %lu)",
+			nr_pages_per_cpu, bytes, page_size, nr_threads);
 		usage();
 	}