Commit-ID: 01a14bda11add9dcd4a59200f13834d634559935 Gitweb: https://git.kernel.org/tip/01a14bda11add9dcd4a59200f13834d634559935 Author: Waiman Long <longman@xxxxxxxxxx> AuthorDate: Thu, 18 Oct 2018 21:45:18 -0400 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Fri, 19 Oct 2018 07:53:18 +0200 locking/lockdep: Make global debug_locks* variables read-mostly Make the frequently used lockdep global variable debug_locks read-mostly. As debug_locks_silent is sometime used together with debug_locks, it is also made read-mostly so that they can be close together. With false cacheline sharing, cacheline contention problem can happen depending on what get put into the same cacheline as debug_locks. Signed-off-by: Waiman Long <longman@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Link: http://lkml.kernel.org/r/1539913518-15598-2-git-send-email-longman@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- include/linux/debug_locks.h | 4 ++-- lib/debug_locks.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h index 120225e9a366..257ab3c92cb8 100644 --- a/include/linux/debug_locks.h +++ b/include/linux/debug_locks.h @@ -8,8 +8,8 @@ struct task_struct; -extern int debug_locks; -extern int debug_locks_silent; +extern int debug_locks __read_mostly; +extern int debug_locks_silent __read_mostly; static inline int __debug_locks_off(void) diff --git a/lib/debug_locks.c b/lib/debug_locks.c index 124fdf238b3d..ce51749cc145 100644 --- a/lib/debug_locks.c +++ b/lib/debug_locks.c @@ -21,7 +21,7 @@ * that would just muddy the log. So we report the first one and * shut up after that. */ -int debug_locks = 1; +int debug_locks __read_mostly = 1; EXPORT_SYMBOL_GPL(debug_locks); /* @@ -29,7 +29,7 @@ EXPORT_SYMBOL_GPL(debug_locks); * 'silent failure': nothing is printed to the console when * a locking bug is detected. */ -int debug_locks_silent; +int debug_locks_silent __read_mostly; EXPORT_SYMBOL_GPL(debug_locks_silent); /*
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