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Subject[PATCH 4.19 01/34] mm: add VM_WARN_ON_ONCE_PAGE() macro
Date
From: Alex Shi <alex.shi@linux.alibaba.com>

[ Upstream commit a4055888629bc0467d12d912cd7c90acdf3d9b12 part ]

Add VM_WARN_ON_ONCE_PAGE() macro.

Link: https://lkml.kernel.org/r/1604283436-18880-3-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Note on stable backport: original commit was titled
mm/memcg: warning on !memcg after readahead page charged
which included uses of this macro in mm/memcontrol.c: here omitted.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/mmdebug.h | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index 2ad72d2c8cc5..5d0767cb424a 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -37,6 +37,18 @@ void dump_mm(const struct mm_struct *mm);
BUG(); \
} \
} while (0)
+#define VM_WARN_ON_ONCE_PAGE(cond, page) ({ \
+ static bool __section(".data.once") __warned; \
+ int __ret_warn_once = !!(cond); \
+ \
+ if (unlikely(__ret_warn_once && !__warned)) { \
+ dump_page(page, "VM_WARN_ON_ONCE_PAGE(" __stringify(cond)")");\
+ __warned = true; \
+ WARN_ON(1); \
+ } \
+ unlikely(__ret_warn_once); \
+})
+
#define VM_WARN_ON(cond) (void)WARN_ON(cond)
#define VM_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond)
#define VM_WARN_ONCE(cond, format...) (void)WARN_ONCE(cond, format)
@@ -48,6 +60,7 @@ void dump_mm(const struct mm_struct *mm);
#define VM_BUG_ON_MM(cond, mm) VM_BUG_ON(cond)
#define VM_WARN_ON(cond) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)
+#define VM_WARN_ON_ONCE_PAGE(cond, page) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN(cond, format...) BUILD_BUG_ON_INVALID(cond)
#endif
--
2.30.2


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