The patch titled
Subject: maple_tree: relax lockdep checks for on-stack trees
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-relax-lockdep-checks-for-on-stack-trees.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-relax-lockdep-checks-for-on-stack-trees.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Subject: maple_tree: relax lockdep checks for on-stack trees
Date: Fri, 14 Jul 2023 15:55:49 -0400
To support early release of the maple tree locks, do not lockdep check the
lock if it is set to NULL. This is intended for the special case on-stack
use of tracking entries and not for general use.
Link: https://lkml.kernel.org/r/20230714195551.894800-3-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oliver Sang <oliver.sang@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/maple_tree.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/include/linux/maple_tree.h~maple_tree-relax-lockdep-checks-for-on-stack-trees
+++ a/include/linux/maple_tree.h
@@ -182,7 +182,9 @@ enum maple_type {
#ifdef CONFIG_LOCKDEP
typedef struct lockdep_map *lockdep_map_p;
-#define mt_lock_is_held(mt) lock_is_held(mt->ma_external_lock)
+#define mt_lock_is_held(mt) \
+ (!(mt)->ma_external_lock || lock_is_held((mt)->ma_external_lock))
+
#define mt_set_external_lock(mt, lock) \
(mt)->ma_external_lock = &(lock)->dep_map
#else
_
Patches currently in -mm which might be from Liam.Howlett@xxxxxxxxxx are
mm-mmap-clean-up-validate_mm-calls.patch
maple_tree-relax-lockdep-checks-for-on-stack-trees.patch
mm-mmap-change-detached-vma-locking-scheme.patch
maple_tree-be-more-strict-about-locking.patch
