The patch titled
docs: static initialization of spinlocks is OK
has been added to the -mm tree. Its filename is
docs-static-initialization-of-spinlocks-is-ok.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: docs: static initialization of spinlocks is OK
From: "Ed L. Cashin" <ecashin@xxxxxxxxxx>
Static initialization of spinlocks is preferable to dynamic initialization
when it is practical. This patch updates documentation for consistency
with comments in spinlock_types.h.
Signed-off-by: Ed L. Cashin <ecashin@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/spinlocks.txt | 20 +++++++++++---------
1 files changed, 11 insertions(+), 9 deletions(-)
diff -puN Documentation/spinlocks.txt~docs-static-initialization-of-spinlocks-is-ok Documentation/spinlocks.txt
--- a/Documentation/spinlocks.txt~docs-static-initialization-of-spinlocks-is-ok
+++ a/Documentation/spinlocks.txt
@@ -1,7 +1,12 @@
-UPDATE March 21 2005 Amit Gud <gud@xxxxxxx>
+SPIN_LOCK_UNLOCKED and RW_LOCK_UNLOCKED defeat lockdep state tracking and
+are hence deprecated.
-Macros SPIN_LOCK_UNLOCKED and RW_LOCK_UNLOCKED are deprecated and will be
-removed soon. So for any new code dynamic initialization should be used:
+Please use DEFINE_SPINLOCK()/DEFINE_RWLOCK() or
+__SPIN_LOCK_UNLOCKED()/__RW_LOCK_UNLOCKED() as appropriate for static
+initialization.
+
+Dynamic initialization, when necessary, may be performed as
+demonstrated below.
spinlock_t xxx_lock;
rwlock_t xxx_rw_lock;
@@ -15,12 +20,9 @@ removed soon. So for any new code dynami
module_init(xxx_init);
-Reasons for deprecation
- - it hurts automatic lock validators
- - it becomes intrusive for the realtime preemption patches
-
-Following discussion is still valid, however, with the dynamic initialization
-of spinlocks instead of static.
+The following discussion is still valid, however, with the dynamic
+initialization of spinlocks or with DEFINE_SPINLOCK, etc., used
+instead of SPIN_LOCK_UNLOCKED.
-----------------------
_
Patches currently in -mm which might be from ecashin@xxxxxxxxxx are
docs-static-initialization-of-spinlocks-is-ok.patch
-
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