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1d44bcb4fd
The whole point of the lockdep dynamic key patch is to allow unused locks to be removed from the lockdep data buffers so that existing buffer space can be reused. However, there is no way to find out how many unused locks are zapped and so we don't know if the zapping process is working properly. Add a new nr_zapped_classes counter to track that and show it in /proc/lockdep_stats. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20200206152408.24165-4-longman@redhat.com
251 lines
6.8 KiB
C
251 lines
6.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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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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#define LOCK_USAGE_READ_MASK 1
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#define LOCK_USAGE_DIR_MASK 2
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#define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK | LOCK_USAGE_DIR_MASK))
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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 LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE |
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static const unsigned long LOCKF_ENABLED_IRQ =
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#include "lockdep_states.h"
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0;
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#undef LOCKDEP_STATE
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#define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE |
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static const unsigned long LOCKF_USED_IN_IRQ =
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#include "lockdep_states.h"
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0;
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#undef LOCKDEP_STATE
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#define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE##_READ |
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static const unsigned long LOCKF_ENABLED_IRQ_READ =
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#include "lockdep_states.h"
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0;
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#undef LOCKDEP_STATE
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#define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE##_READ |
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static const unsigned long LOCKF_USED_IN_IRQ_READ =
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#include "lockdep_states.h"
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0;
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#undef LOCKDEP_STATE
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#define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ | LOCKF_ENABLED_IRQ_READ)
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#define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ | LOCKF_USED_IN_IRQ_READ)
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#define LOCKF_IRQ (LOCKF_ENABLED_IRQ | LOCKF_USED_IN_IRQ)
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#define LOCKF_IRQ_READ (LOCKF_ENABLED_IRQ_READ | LOCKF_USED_IN_IRQ_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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#define STACK_TRACE_HASH_SIZE 8192
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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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#define STACK_TRACE_HASH_SIZE 16384
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#endif
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/*
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* Bit definitions for lock_chain.irq_context
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*/
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#define LOCK_CHAIN_SOFTIRQ_CONTEXT (1 << 0)
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#define LOCK_CHAIN_HARDIRQ_CONTEXT (1 << 1)
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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(const struct lockdep_subclass_key *key,
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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_zapped_classes;
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extern unsigned long nr_list_entries;
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long lockdep_next_lockchain(long i);
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unsigned long lock_chain_count(void);
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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_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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#ifdef CONFIG_TRACE_IRQFLAGS
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u64 lockdep_stack_trace_count(void);
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u64 lockdep_stack_hash_count(void);
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#endif
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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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unsigned long chain_lookup_hits;
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unsigned int chain_lookup_misses;
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unsigned long hardirqs_on_events;
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unsigned long hardirqs_off_events;
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unsigned long redundant_hardirqs_on;
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unsigned long redundant_hardirqs_off;
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unsigned long softirqs_on_events;
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unsigned long softirqs_off_events;
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unsigned long redundant_softirqs_on;
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unsigned long redundant_softirqs_off;
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int nr_unused_locks;
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unsigned int nr_redundant_checks;
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unsigned int nr_redundant;
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unsigned int nr_cyclic_checks;
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unsigned int nr_find_usage_forwards_checks;
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unsigned int nr_find_usage_backwards_checks;
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/*
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* Per lock class locking operation stat counts
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*/
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unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
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};
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DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
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extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
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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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static inline void debug_class_ops_inc(struct lock_class *class)
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{
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int idx;
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idx = class - lock_classes;
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__debug_atomic_inc(lock_class_ops[idx]);
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}
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static inline unsigned long debug_class_ops_read(struct lock_class *class)
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{
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int idx, cpu;
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unsigned long ops = 0;
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idx = class - lock_classes;
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for_each_possible_cpu(cpu)
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ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
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return ops;
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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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# define debug_class_ops_inc(ptr) do { } while (0)
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#endif
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