From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: mmap_lock: fix disabling preemption directly
The commit 832b50725373 ("mm: mmap_lock: use local locks instead of
disabling preemption") fix a bug by using local locks. But commit
d01079f3d0c0 ("mm/mmap_lock: remove dead code for !CONFIG_TRACING
configurations") changes those lines to original version. I guess it is
introduced by the conflicts fixing on merging.
Link: https://lkml.kernel.org/r/20210720074228.76342-1-songmuchun@xxxxxxxxxxxxx
Fixes: d01079f3d0c0 ("mm/mmap_lock: remove dead code for !CONFIG_TRACING configurations")
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Yang Shi <shy828301@xxxxxxxxx>
Reviewed-by: Pankaj Gupta <pankaj.gupta@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap_lock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/mmap_lock.c~mm-mmap_lock-fix-disabling-preemption-directly
+++ a/mm/mmap_lock.c
@@ -156,14 +156,14 @@ static inline void put_memcg_path_buf(vo
#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \
do { \
const char *memcg_path; \
- preempt_disable(); \
+ local_lock(&memcg_paths.lock); \
memcg_path = get_mm_memcg_path(mm); \
trace_mmap_lock_##type(mm, \
memcg_path != NULL ? memcg_path : "", \
##__VA_ARGS__); \
if (likely(memcg_path != NULL)) \
put_memcg_path_buf(); \
- preempt_enable(); \
+ local_unlock(&memcg_paths.lock); \
} while (0)
#else /* !CONFIG_MEMCG */
_
