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Waiman Long
01a14bda11
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 <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
49 lines
1.2 KiB
C
49 lines
1.2 KiB
C
/*
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* lib/debug_locks.c
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*
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* Generic place for common debugging facilities for various locks:
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* spinlocks, rwlocks, mutexes and rwsems.
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*
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* Started by Ingo Molnar:
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*
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* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <[email protected]>
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*/
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#include <linux/rwsem.h>
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#include <linux/mutex.h>
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#include <linux/export.h>
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#include <linux/spinlock.h>
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#include <linux/debug_locks.h>
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/*
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* We want to turn all lock-debugging facilities on/off at once,
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* via a global flag. The reason is that once a single bug has been
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* detected and reported, there might be cascade of followup bugs
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* that would just muddy the log. So we report the first one and
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* shut up after that.
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*/
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int debug_locks __read_mostly = 1;
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EXPORT_SYMBOL_GPL(debug_locks);
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/*
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* The locking-testsuite uses <debug_locks_silent> to get a
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* 'silent failure': nothing is printed to the console when
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* a locking bug is detected.
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*/
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int debug_locks_silent __read_mostly;
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EXPORT_SYMBOL_GPL(debug_locks_silent);
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/*
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* Generic 'turn off all lock debugging' function:
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*/
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int debug_locks_off(void)
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{
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if (debug_locks && __debug_locks_off()) {
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if (!debug_locks_silent) {
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console_verbose();
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return 1;
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}
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(debug_locks_off);
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