ae813308f4
Two boots + a make defconfig, the first didn't have the redundant bit in, the second did: lock-classes: 1168 1169 [max: 8191] direct dependencies: 7688 5812 [max: 32768] indirect dependencies: 25492 25937 all direct dependencies: 220113 217512 dependency chains: 9005 9008 [max: 65536] dependency chain hlocks: 34450 34366 [max: 327680] in-hardirq chains: 55 51 in-softirq chains: 371 378 in-process chains: 8579 8579 stack-trace entries: 108073 88474 [max: 524288] combined max dependencies: 178738560 169094640 max locking depth: 15 15 max bfs queue depth: 320 329 cyclic checks: 9123 9190 redundant checks: 5046 redundant links: 1828 find-mask forwards checks: 2564 2599 find-mask backwards checks: 39521 39789 So it saves nearly 2k links and a fair chunk of stack-trace entries, but as expected, makes no real difference on the indirect dependencies. At the same time, you see the max BFS depth increase, which is also expected, although it could easily be boot variance -- these numbers are not entirely stable between boots. The down side is that the cycles in the graph become larger and thus the reports harder to read. XXX: do we want this as a CONFIG variable, implied by LOCKDEP_SMALL? Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: iamjoonsoo.kim@lge.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Link: http://lkml.kernel.org/r/20170303091338.GH6536@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
187 lines
5.0 KiB
C
187 lines
5.0 KiB
C
/*
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* kernel/lockdep_internals.h
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*
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* Runtime locking correctness validator
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*
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* lockdep subsystem internal functions and variables.
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*/
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/*
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* Lock-class usage-state bits:
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*/
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enum lock_usage_bit {
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#define LOCKDEP_STATE(__STATE) \
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LOCK_USED_IN_##__STATE, \
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LOCK_USED_IN_##__STATE##_READ, \
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LOCK_ENABLED_##__STATE, \
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LOCK_ENABLED_##__STATE##_READ,
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#include "lockdep_states.h"
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#undef LOCKDEP_STATE
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LOCK_USED,
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LOCK_USAGE_STATES
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};
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/*
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* Usage-state bitmasks:
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*/
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#define __LOCKF(__STATE) LOCKF_##__STATE = (1 << LOCK_##__STATE),
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enum {
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#define LOCKDEP_STATE(__STATE) \
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__LOCKF(USED_IN_##__STATE) \
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__LOCKF(USED_IN_##__STATE##_READ) \
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__LOCKF(ENABLED_##__STATE) \
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__LOCKF(ENABLED_##__STATE##_READ)
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#include "lockdep_states.h"
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#undef LOCKDEP_STATE
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__LOCKF(USED)
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};
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#define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ)
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#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
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#define LOCKF_ENABLED_IRQ_READ \
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(LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ)
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#define LOCKF_USED_IN_IRQ_READ \
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(LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
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/*
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* CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
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* .data and .bss to fit in required 32MB limit for the kernel. With
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* CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
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* So, reduce the static allocations for lockdeps related structures so that
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* everything fits in current required size limit.
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*/
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#ifdef CONFIG_LOCKDEP_SMALL
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/*
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* MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
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* we track.
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*
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* We use the per-lock dependency maps in two ways: we grow it by adding
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* every to-be-taken lock to all currently held lock's own dependency
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* table (if it's not there yet), and we check it for lock order
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* conflicts and deadlocks.
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*/
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#define MAX_LOCKDEP_ENTRIES 16384UL
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#define MAX_LOCKDEP_CHAINS_BITS 15
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#define MAX_STACK_TRACE_ENTRIES 262144UL
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#else
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#define MAX_LOCKDEP_ENTRIES 32768UL
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#define MAX_LOCKDEP_CHAINS_BITS 16
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/*
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* Stack-trace: tightly packed array of stack backtrace
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* addresses. Protected by the hash_lock.
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*/
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#define MAX_STACK_TRACE_ENTRIES 524288UL
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#endif
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#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
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#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
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extern struct list_head all_lock_classes;
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extern struct lock_chain lock_chains[];
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#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
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extern void get_usage_chars(struct lock_class *class,
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char usage[LOCK_USAGE_CHARS]);
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extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
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struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
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extern unsigned long nr_lock_classes;
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extern unsigned long nr_list_entries;
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extern unsigned long nr_lock_chains;
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extern int nr_chain_hlocks;
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extern unsigned long nr_stack_trace_entries;
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extern unsigned int nr_hardirq_chains;
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extern unsigned int nr_softirq_chains;
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extern unsigned int nr_process_chains;
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extern unsigned int max_lockdep_depth;
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extern unsigned int max_recursion_depth;
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extern unsigned int max_bfs_queue_depth;
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#ifdef CONFIG_PROVE_LOCKING
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extern unsigned long lockdep_count_forward_deps(struct lock_class *);
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extern unsigned long lockdep_count_backward_deps(struct lock_class *);
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#else
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static inline unsigned long
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lockdep_count_forward_deps(struct lock_class *class)
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{
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return 0;
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}
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static inline unsigned long
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lockdep_count_backward_deps(struct lock_class *class)
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{
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return 0;
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}
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#endif
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#ifdef CONFIG_DEBUG_LOCKDEP
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#include <asm/local.h>
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/*
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* Various lockdep statistics.
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* We want them per cpu as they are often accessed in fast path
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* and we want to avoid too much cache bouncing.
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*/
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struct lockdep_stats {
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int chain_lookup_hits;
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int chain_lookup_misses;
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int hardirqs_on_events;
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int hardirqs_off_events;
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int redundant_hardirqs_on;
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int redundant_hardirqs_off;
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int softirqs_on_events;
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int softirqs_off_events;
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int redundant_softirqs_on;
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int redundant_softirqs_off;
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int nr_unused_locks;
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int nr_redundant_checks;
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int nr_redundant;
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int nr_cyclic_checks;
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int nr_cyclic_check_recursions;
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int nr_find_usage_forwards_checks;
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int nr_find_usage_forwards_recursions;
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int nr_find_usage_backwards_checks;
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int nr_find_usage_backwards_recursions;
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};
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DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
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#define __debug_atomic_inc(ptr) \
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this_cpu_inc(lockdep_stats.ptr);
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#define debug_atomic_inc(ptr) { \
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WARN_ON_ONCE(!irqs_disabled()); \
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__this_cpu_inc(lockdep_stats.ptr); \
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}
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#define debug_atomic_dec(ptr) { \
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WARN_ON_ONCE(!irqs_disabled()); \
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__this_cpu_dec(lockdep_stats.ptr); \
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}
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#define debug_atomic_read(ptr) ({ \
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struct lockdep_stats *__cpu_lockdep_stats; \
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unsigned long long __total = 0; \
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int __cpu; \
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for_each_possible_cpu(__cpu) { \
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__cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \
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__total += __cpu_lockdep_stats->ptr; \
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} \
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__total; \
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})
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#else
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# define __debug_atomic_inc(ptr) do { } while (0)
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# define debug_atomic_inc(ptr) do { } while (0)
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# define debug_atomic_dec(ptr) do { } while (0)
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# define debug_atomic_read(ptr) 0
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#endif
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