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@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1539913518-15598-2-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Waiman Long 2018-10-18 21:45:18 -04:00 committed by Ingo Molnar
parent 9506a7425b
commit 01a14bda11
2 changed files with 4 additions and 4 deletions

View File

@ -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)

View File

@ -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);
/*