The patch titled
Lockdep treats down_write_trylock like regular down_write
has been added to the -mm tree. Its filename is
lockdep-treats-down_write_trylock-like-regular-down_write.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Lockdep treats down_write_trylock like regular down_write
From: Pavel Emelianov <xemul@xxxxx>
This causes constructions like
down_write(&mm1->mmap_sem);
if (down_write_trylock(&mm2->mmap_sem)) {
...
up_write(&mm2->mmap_sem);
}
up_write(&mm1->mmap_sem);
generate a lockdep warning about circular locking dependence.
Call rwsem_acquire() with trylock set to 1.
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/rwsem.c | 2 +-
1 files changed, 1 insertion(+), 1 deletion(-)
diff -puN kernel/rwsem.c~lockdep-treats-down_write_trylock-like-regular-down_write kernel/rwsem.c
--- a/kernel/rwsem.c~lockdep-treats-down_write_trylock-like-regular-down_write
+++ a/kernel/rwsem.c
@@ -60,7 +60,7 @@ int down_write_trylock(struct rw_semapho
int ret = __down_write_trylock(sem);
if (ret == 1)
- rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
+ rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_);
return ret;
}
_
Patches currently in -mm which might be from xemul@xxxxx are
lockdep-treats-down_write_trylock-like-regular-down_write.patch
-
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