[PATCH mm-unstable v1] selftests/mm: define MADV_PAGEOUT to fix compilation issues

[David Hildenbrand]

If MADV_PAGEOUT is not defined (e.g., on AlmaLinux 8), compilation will
fail. Let's fix that like khugepaged.c does by conditionally defining
MADV_PAGEOUT.

Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@xxxxxxxxxxxx>
Fixes: 69c66add5663 ("selftests/vm: anon_cow: test COW handling of anonymous memory")
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 tools/testing/selftests/mm/cow.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index 16216d893d96..0eb2e8180aa5 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -30,6 +30,9 @@
 #include "../kselftest.h"
 #include "vm_util.h"
 
+#ifndef MADV_PAGEOUT
+#define MADV_PAGEOUT 21
+#endif
 #ifndef MADV_COLLAPSE
 #define MADV_COLLAPSE 25
 #endif
-- 
2.39.0