It might be a corner case when we add UINT_MAX as 64-bit unsigned value
to the percpu variable as it's not the same as -1 (ULONG_LONG_MAX).
Add a test case for that.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
lib/percpu_test.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/lib/percpu_test.c b/lib/percpu_test.c
index 4a3d70bbc1a0..ce7124b16dab 100644
--- a/lib/percpu_test.c
+++ b/lib/percpu_test.c
@@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/limits.h>
#include <linux/module.h>
/* validate @native and @pcp counter values match @expected */
@@ -24,8 +25,9 @@ static int __init percpu_test_init(void)
* +ul_one/-ul_one below would replace with inc/dec instructions.
*/
volatile unsigned int ui_one = 1;
- long l = 0;
+ unsigned long long ull = 0;
unsigned long ul = 0;
+ long l = 0;
pr_info("percpu test start\n");
@@ -112,6 +114,13 @@ static int __init percpu_test_init(void)
CHECK(ul, ulong_counter, -1);
CHECK(ul, ulong_counter, ULONG_MAX);
+ ul = ull = 0;
+ __this_cpu_write(ulong_counter, 0);
+
+ ul = ull += UINT_MAX;
+ __this_cpu_add(ulong_counter, ull);
+ CHECK(ul, ulong_counter, UINT_MAX);
+
ul = 3;
__this_cpu_write(ulong_counter, 3);
--
2.43.0.rc1.1336.g36b5255a03ac
