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From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, Liam.Howlett@oracle.com,
	linux-mm@kvack.org, mm-commits@vger.kernel.org,
	rostedt@goodmis.org, torvalds@linux-foundation.org,
	vbabka@suse.cz, walken.cr@gmail.com, willy@infradead.org
Subject: [patch 5/8] mmap_lock: change trace and locking order
Date: Wed, 08 Sep 2021 18:10:14 -0700	[thread overview]
Message-ID: <20210909011014.JJu-mAZB6%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210908180859.d523d4bb4ad8eec11c61500d@linux-foundation.org>

From: Liam Howlett <liam.howlett@oracle.com>
Subject: mmap_lock: change trace and locking order

Print to the trace log before releasing the lock to avoid racing with
other trace log printers of the same lock type.

Link: https://lkml.kernel.org/r/20210903022041.1843024-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michel Lespinasse <walken.cr@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mmap_lock.h |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/include/linux/mmap_lock.h~mmap_lock-change-trace-and-locking-order
+++ a/include/linux/mmap_lock.h
@@ -101,14 +101,14 @@ static inline bool mmap_write_trylock(st
 
 static inline void mmap_write_unlock(struct mm_struct *mm)
 {
-	up_write(&mm->mmap_lock);
 	__mmap_lock_trace_released(mm, true);
+	up_write(&mm->mmap_lock);
 }
 
 static inline void mmap_write_downgrade(struct mm_struct *mm)
 {
-	downgrade_write(&mm->mmap_lock);
 	__mmap_lock_trace_acquire_returned(mm, false, true);
+	downgrade_write(&mm->mmap_lock);
 }
 
 static inline void mmap_read_lock(struct mm_struct *mm)
@@ -140,8 +140,8 @@ static inline bool mmap_read_trylock(str
 
 static inline void mmap_read_unlock(struct mm_struct *mm)
 {
-	up_read(&mm->mmap_lock);
 	__mmap_lock_trace_released(mm, false);
+	up_read(&mm->mmap_lock);
 }
 
 static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)
@@ -155,8 +155,8 @@ static inline bool mmap_read_trylock_non
 
 static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
 {
-	up_read_non_owner(&mm->mmap_lock);
 	__mmap_lock_trace_released(mm, false);
+	up_read_non_owner(&mm->mmap_lock);
 }
 
 static inline void mmap_assert_locked(struct mm_struct *mm)
_

  parent reply	other threads:[~2021-09-09  1:10 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-09  1:08 incoming Andrew Morton
2021-09-09  1:10 ` [patch 1/8] mm/hmm: bypass devmap pte when all pfn requested flags are fulfilled Andrew Morton
2021-09-09  1:10 ` [patch 2/8] mm/hugetlb: initialize hugetlb_usage in mm_init Andrew Morton
2021-09-09  1:10 ` [patch 3/8] mm,vmscan: fix divide by zero in get_scan_count Andrew Morton
2021-09-09  1:10 ` [patch 4/8] mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype Andrew Morton
2021-09-09  1:10 ` Andrew Morton [this message]
2021-09-09 12:56   ` [patch 5/8] mmap_lock: change trace and locking order Liam Howlett
2021-09-09  1:10 ` [patch 6/8] mm/kmemleak: allow __GFP_NOLOCKDEP passed to kmemleak's gfp Andrew Morton
2021-09-09  1:10 ` [patch 7/8] mm/mempolicy: fix a race between offset_il_node and mpol_rebind_task Andrew Morton
2021-09-09  1:10 ` [patch 8/8] nds32/setup: remove unused memblock_region variable in setup_memory() Andrew Morton

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