lockdep: BFS cleanup
Some cleanups of the lockdep code after the BFS series: - Remove the last traces of the generation id - Fixup comment style - Move the bfs routines into lockdep.c - Cleanup the bfs routines [ tom.leiming@gmail.com: Fix crash ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1246201486-7308-11-git-send-email-tom.leiming@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
parent
12f3dfd022
commit
af01296145
|
|
@ -58,7 +58,6 @@ struct lock_class {
|
|||
|
||||
struct lockdep_subclass_key *key;
|
||||
unsigned int subclass;
|
||||
unsigned int dep_gen_id;
|
||||
|
||||
/*
|
||||
* IRQ/softirq usage tracking bits:
|
||||
|
|
@ -150,9 +149,9 @@ struct lock_list {
|
|||
struct stack_trace trace;
|
||||
int distance;
|
||||
|
||||
/*The parent field is used to implement breadth-first search,and
|
||||
*the bit 0 is reused to indicate if the lock has been accessed
|
||||
*in BFS.
|
||||
/*
|
||||
* The parent field is used to implement breadth-first search, and the
|
||||
* bit 0 is reused to indicate if the lock has been accessed in BFS.
|
||||
*/
|
||||
struct lock_list *parent;
|
||||
};
|
||||
|
|
|
|||
284
kernel/lockdep.c
284
kernel/lockdep.c
|
|
@ -43,6 +43,7 @@
|
|||
#include <linux/ftrace.h>
|
||||
#include <linux/stringify.h>
|
||||
#include <linux/bitops.h>
|
||||
|
||||
#include <asm/sections.h>
|
||||
|
||||
#include "lockdep_internals.h"
|
||||
|
|
@ -118,7 +119,7 @@ static inline int debug_locks_off_graph_unlock(void)
|
|||
static int lockdep_initialized;
|
||||
|
||||
unsigned long nr_list_entries;
|
||||
struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
|
||||
static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
|
||||
|
||||
/*
|
||||
* All data structures here are protected by the global debug_lock.
|
||||
|
|
@ -390,19 +391,6 @@ unsigned int nr_process_chains;
|
|||
unsigned int max_lockdep_depth;
|
||||
unsigned int max_recursion_depth;
|
||||
|
||||
static unsigned int lockdep_dependency_gen_id;
|
||||
|
||||
static bool lockdep_dependency_visit(struct lock_class *source,
|
||||
unsigned int depth)
|
||||
{
|
||||
if (!depth)
|
||||
lockdep_dependency_gen_id++;
|
||||
if (source->dep_gen_id == lockdep_dependency_gen_id)
|
||||
return true;
|
||||
source->dep_gen_id = lockdep_dependency_gen_id;
|
||||
return false;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_DEBUG_LOCKDEP
|
||||
/*
|
||||
* We cannot printk in early bootup code. Not even early_printk()
|
||||
|
|
@ -551,88 +539,6 @@ static void lockdep_print_held_locks(struct task_struct *curr)
|
|||
}
|
||||
}
|
||||
|
||||
static void print_lock_class_header(struct lock_class *class, int depth)
|
||||
{
|
||||
int bit;
|
||||
|
||||
printk("%*s->", depth, "");
|
||||
print_lock_name(class);
|
||||
printk(" ops: %lu", class->ops);
|
||||
printk(" {\n");
|
||||
|
||||
for (bit = 0; bit < LOCK_USAGE_STATES; bit++) {
|
||||
if (class->usage_mask & (1 << bit)) {
|
||||
int len = depth;
|
||||
|
||||
len += printk("%*s %s", depth, "", usage_str[bit]);
|
||||
len += printk(" at:\n");
|
||||
print_stack_trace(class->usage_traces + bit, len);
|
||||
}
|
||||
}
|
||||
printk("%*s }\n", depth, "");
|
||||
|
||||
printk("%*s ... key at: ",depth,"");
|
||||
print_ip_sym((unsigned long)class->key);
|
||||
}
|
||||
|
||||
/*
|
||||
* printk the shortest lock dependencies from @start to @end in reverse order:
|
||||
*/
|
||||
static void __used
|
||||
print_shortest_lock_dependencies(struct lock_list *leaf,
|
||||
struct lock_list *root)
|
||||
{
|
||||
struct lock_list *entry = leaf;
|
||||
int depth;
|
||||
|
||||
/*compute depth from generated tree by BFS*/
|
||||
depth = get_lock_depth(leaf);
|
||||
|
||||
do {
|
||||
print_lock_class_header(entry->class, depth);
|
||||
printk("%*s ... acquired at:\n", depth, "");
|
||||
print_stack_trace(&entry->trace, 2);
|
||||
printk("\n");
|
||||
|
||||
if (depth == 0 && (entry != root)) {
|
||||
printk("lockdep:%s bad BFS generated tree\n", __func__);
|
||||
break;
|
||||
}
|
||||
|
||||
entry = get_lock_parent(entry);
|
||||
depth--;
|
||||
} while (entry && (depth >= 0));
|
||||
|
||||
return;
|
||||
}
|
||||
/*
|
||||
* printk all lock dependencies starting at <entry>:
|
||||
*/
|
||||
static void __used
|
||||
print_lock_dependencies(struct lock_class *class, int depth)
|
||||
{
|
||||
struct lock_list *entry;
|
||||
|
||||
if (lockdep_dependency_visit(class, depth))
|
||||
return;
|
||||
|
||||
if (DEBUG_LOCKS_WARN_ON(depth >= 20))
|
||||
return;
|
||||
|
||||
print_lock_class_header(class, depth);
|
||||
|
||||
list_for_each_entry(entry, &class->locks_after, entry) {
|
||||
if (DEBUG_LOCKS_WARN_ON(!entry->class))
|
||||
return;
|
||||
|
||||
print_lock_dependencies(entry->class, depth + 1);
|
||||
|
||||
printk("%*s ... acquired at:\n",depth,"");
|
||||
print_stack_trace(&entry->trace, 2);
|
||||
printk("\n");
|
||||
}
|
||||
}
|
||||
|
||||
static void print_kernel_version(void)
|
||||
{
|
||||
printk("%s %.*s\n", init_utsname()->release,
|
||||
|
|
@ -927,14 +833,106 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
|
|||
return 1;
|
||||
}
|
||||
|
||||
unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)];
|
||||
static struct circular_queue lock_cq;
|
||||
/*For good efficiency of modular, we use power of 2*/
|
||||
#define MAX_CIRCULAR_QUEUE_SIZE 4096UL
|
||||
#define CQ_MASK (MAX_CIRCULAR_QUEUE_SIZE-1)
|
||||
|
||||
/* The circular_queue and helpers is used to implement the
|
||||
* breadth-first search(BFS)algorithem, by which we can build
|
||||
* the shortest path from the next lock to be acquired to the
|
||||
* previous held lock if there is a circular between them.
|
||||
* */
|
||||
struct circular_queue {
|
||||
unsigned long element[MAX_CIRCULAR_QUEUE_SIZE];
|
||||
unsigned int front, rear;
|
||||
};
|
||||
|
||||
static struct circular_queue lock_cq;
|
||||
static unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)];
|
||||
|
||||
unsigned int max_bfs_queue_depth;
|
||||
|
||||
static inline void __cq_init(struct circular_queue *cq)
|
||||
{
|
||||
cq->front = cq->rear = 0;
|
||||
bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES);
|
||||
}
|
||||
|
||||
static inline int __cq_empty(struct circular_queue *cq)
|
||||
{
|
||||
return (cq->front == cq->rear);
|
||||
}
|
||||
|
||||
static inline int __cq_full(struct circular_queue *cq)
|
||||
{
|
||||
return ((cq->rear + 1) & CQ_MASK) == cq->front;
|
||||
}
|
||||
|
||||
static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem)
|
||||
{
|
||||
if (__cq_full(cq))
|
||||
return -1;
|
||||
|
||||
cq->element[cq->rear] = elem;
|
||||
cq->rear = (cq->rear + 1) & CQ_MASK;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem)
|
||||
{
|
||||
if (__cq_empty(cq))
|
||||
return -1;
|
||||
|
||||
*elem = cq->element[cq->front];
|
||||
cq->front = (cq->front + 1) & CQ_MASK;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline unsigned int __cq_get_elem_count(struct circular_queue *cq)
|
||||
{
|
||||
return (cq->rear - cq->front) & CQ_MASK;
|
||||
}
|
||||
|
||||
static inline void mark_lock_accessed(struct lock_list *lock,
|
||||
struct lock_list *parent)
|
||||
{
|
||||
unsigned long nr;
|
||||
nr = lock - list_entries;
|
||||
WARN_ON(nr >= nr_list_entries);
|
||||
lock->parent = parent;
|
||||
set_bit(nr, bfs_accessed);
|
||||
}
|
||||
|
||||
static inline unsigned long lock_accessed(struct lock_list *lock)
|
||||
{
|
||||
unsigned long nr;
|
||||
nr = lock - list_entries;
|
||||
WARN_ON(nr >= nr_list_entries);
|
||||
return test_bit(nr, bfs_accessed);
|
||||
}
|
||||
|
||||
static inline struct lock_list *get_lock_parent(struct lock_list *child)
|
||||
{
|
||||
return child->parent;
|
||||
}
|
||||
|
||||
static inline int get_lock_depth(struct lock_list *child)
|
||||
{
|
||||
int depth = 0;
|
||||
struct lock_list *parent;
|
||||
|
||||
while ((parent = get_lock_parent(child))) {
|
||||
child = parent;
|
||||
depth++;
|
||||
}
|
||||
return depth;
|
||||
}
|
||||
|
||||
static int __bfs(struct lock_list *source_entry,
|
||||
void *data,
|
||||
int (*match)(struct lock_list *entry, void *data),
|
||||
struct lock_list **target_entry,
|
||||
int forward)
|
||||
void *data,
|
||||
int (*match)(struct lock_list *entry, void *data),
|
||||
struct lock_list **target_entry,
|
||||
int forward)
|
||||
{
|
||||
struct lock_list *entry;
|
||||
struct list_head *head;
|
||||
|
|
@ -1202,14 +1200,6 @@ check_noncircular(struct lock_list *root, struct lock_class *target,
|
|||
* without creating any illegal irq-safe -> irq-unsafe lock dependency.
|
||||
*/
|
||||
|
||||
|
||||
#define BFS_PROCESS_RET(ret) do { \
|
||||
if (ret < 0) \
|
||||
return print_bfs_bug(ret); \
|
||||
if (ret == 1) \
|
||||
return 1; \
|
||||
} while (0)
|
||||
|
||||
static inline int usage_match(struct lock_list *entry, void *bit)
|
||||
{
|
||||
return entry->class->usage_mask & (1 << (enum lock_usage_bit)bit);
|
||||
|
|
@ -1263,6 +1253,60 @@ find_usage_backwards(struct lock_list *root, enum lock_usage_bit bit,
|
|||
return result;
|
||||
}
|
||||
|
||||
static void print_lock_class_header(struct lock_class *class, int depth)
|
||||
{
|
||||
int bit;
|
||||
|
||||
printk("%*s->", depth, "");
|
||||
print_lock_name(class);
|
||||
printk(" ops: %lu", class->ops);
|
||||
printk(" {\n");
|
||||
|
||||
for (bit = 0; bit < LOCK_USAGE_STATES; bit++) {
|
||||
if (class->usage_mask & (1 << bit)) {
|
||||
int len = depth;
|
||||
|
||||
len += printk("%*s %s", depth, "", usage_str[bit]);
|
||||
len += printk(" at:\n");
|
||||
print_stack_trace(class->usage_traces + bit, len);
|
||||
}
|
||||
}
|
||||
printk("%*s }\n", depth, "");
|
||||
|
||||
printk("%*s ... key at: ",depth,"");
|
||||
print_ip_sym((unsigned long)class->key);
|
||||
}
|
||||
|
||||
/*
|
||||
* printk the shortest lock dependencies from @start to @end in reverse order:
|
||||
*/
|
||||
static void __used
|
||||
print_shortest_lock_dependencies(struct lock_list *leaf,
|
||||
struct lock_list *root)
|
||||
{
|
||||
struct lock_list *entry = leaf;
|
||||
int depth;
|
||||
|
||||
/*compute depth from generated tree by BFS*/
|
||||
depth = get_lock_depth(leaf);
|
||||
|
||||
do {
|
||||
print_lock_class_header(entry->class, depth);
|
||||
printk("%*s ... acquired at:\n", depth, "");
|
||||
print_stack_trace(&entry->trace, 2);
|
||||
printk("\n");
|
||||
|
||||
if (depth == 0 && (entry != root)) {
|
||||
printk("lockdep:%s bad BFS generated tree\n", __func__);
|
||||
break;
|
||||
}
|
||||
|
||||
entry = get_lock_parent(entry);
|
||||
depth--;
|
||||
} while (entry && (depth >= 0));
|
||||
|
||||
return;
|
||||
}
|
||||
|
||||
static int
|
||||
print_bad_irq_dependency(struct task_struct *curr,
|
||||
|
|
@ -1349,12 +1393,18 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
|
|||
|
||||
this.class = hlock_class(prev);
|
||||
ret = find_usage_backwards(&this, bit_backwards, &target_entry);
|
||||
BFS_PROCESS_RET(ret);
|
||||
if (ret < 0)
|
||||
return print_bfs_bug(ret);
|
||||
if (ret == 1)
|
||||
return ret;
|
||||
|
||||
that.parent = NULL;
|
||||
that.class = hlock_class(next);
|
||||
ret = find_usage_forwards(&that, bit_forwards, &target_entry1);
|
||||
BFS_PROCESS_RET(ret);
|
||||
if (ret < 0)
|
||||
return print_bfs_bug(ret);
|
||||
if (ret == 1)
|
||||
return ret;
|
||||
|
||||
return print_bad_irq_dependency(curr, &this, &that,
|
||||
target_entry, target_entry1,
|
||||
|
|
@ -2038,7 +2088,10 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this,
|
|||
root.parent = NULL;
|
||||
root.class = hlock_class(this);
|
||||
ret = find_usage_forwards(&root, bit, &target_entry);
|
||||
BFS_PROCESS_RET(ret);
|
||||
if (ret < 0)
|
||||
return print_bfs_bug(ret);
|
||||
if (ret == 1)
|
||||
return ret;
|
||||
|
||||
return print_irq_inversion_bug(curr, &root, target_entry,
|
||||
this, 1, irqclass);
|
||||
|
|
@ -2059,7 +2112,10 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
|
|||
root.parent = NULL;
|
||||
root.class = hlock_class(this);
|
||||
ret = find_usage_backwards(&root, bit, &target_entry);
|
||||
BFS_PROCESS_RET(ret);
|
||||
if (ret < 0)
|
||||
return print_bfs_bug(ret);
|
||||
if (ret == 1)
|
||||
return ret;
|
||||
|
||||
return print_irq_inversion_bug(curr, &root, target_entry,
|
||||
this, 1, irqclass);
|
||||
|
|
|
|||
|
|
@ -91,6 +91,8 @@ extern unsigned int nr_process_chains;
|
|||
extern unsigned int max_lockdep_depth;
|
||||
extern unsigned int max_recursion_depth;
|
||||
|
||||
extern unsigned int max_bfs_queue_depth;
|
||||
|
||||
#ifdef CONFIG_PROVE_LOCKING
|
||||
extern unsigned long lockdep_count_forward_deps(struct lock_class *);
|
||||
extern unsigned long lockdep_count_backward_deps(struct lock_class *);
|
||||
|
|
@ -136,98 +138,3 @@ extern atomic_t nr_find_usage_backwards_recursions;
|
|||
# define debug_atomic_dec(ptr) do { } while (0)
|
||||
# define debug_atomic_read(ptr) 0
|
||||
#endif
|
||||
|
||||
|
||||
extern unsigned int max_bfs_queue_depth;
|
||||
extern unsigned long nr_list_entries;
|
||||
extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
|
||||
extern unsigned long bfs_accessed[];
|
||||
|
||||
/*For good efficiency of modular, we use power of 2*/
|
||||
#define MAX_CIRCULAR_QUE_SIZE 4096UL
|
||||
|
||||
/* The circular_queue and helpers is used to implement the
|
||||
* breadth-first search(BFS)algorithem, by which we can build
|
||||
* the shortest path from the next lock to be acquired to the
|
||||
* previous held lock if there is a circular between them.
|
||||
* */
|
||||
struct circular_queue{
|
||||
unsigned long element[MAX_CIRCULAR_QUE_SIZE];
|
||||
unsigned int front, rear;
|
||||
};
|
||||
|
||||
static inline void __cq_init(struct circular_queue *cq)
|
||||
{
|
||||
cq->front = cq->rear = 0;
|
||||
bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES);
|
||||
}
|
||||
|
||||
static inline int __cq_empty(struct circular_queue *cq)
|
||||
{
|
||||
return (cq->front == cq->rear);
|
||||
}
|
||||
|
||||
static inline int __cq_full(struct circular_queue *cq)
|
||||
{
|
||||
return ((cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1)) == cq->front;
|
||||
}
|
||||
|
||||
static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem)
|
||||
{
|
||||
if (__cq_full(cq))
|
||||
return -1;
|
||||
|
||||
cq->element[cq->rear] = elem;
|
||||
cq->rear = (cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem)
|
||||
{
|
||||
if (__cq_empty(cq))
|
||||
return -1;
|
||||
|
||||
*elem = cq->element[cq->front];
|
||||
cq->front = (cq->front + 1)&(MAX_CIRCULAR_QUE_SIZE-1);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline unsigned int __cq_get_elem_count(struct circular_queue *cq)
|
||||
{
|
||||
return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1);
|
||||
}
|
||||
|
||||
static inline void mark_lock_accessed(struct lock_list *lock,
|
||||
struct lock_list *parent)
|
||||
{
|
||||
unsigned long nr;
|
||||
nr = lock - list_entries;
|
||||
WARN_ON(nr >= nr_list_entries);
|
||||
lock->parent = parent;
|
||||
set_bit(nr, bfs_accessed);
|
||||
}
|
||||
|
||||
static inline unsigned long lock_accessed(struct lock_list *lock)
|
||||
{
|
||||
unsigned long nr;
|
||||
nr = lock - list_entries;
|
||||
WARN_ON(nr >= nr_list_entries);
|
||||
return test_bit(nr, bfs_accessed);
|
||||
}
|
||||
|
||||
static inline struct lock_list *get_lock_parent(struct lock_list *child)
|
||||
{
|
||||
return child->parent;
|
||||
}
|
||||
|
||||
static inline int get_lock_depth(struct lock_list *child)
|
||||
{
|
||||
int depth = 0;
|
||||
struct lock_list *parent;
|
||||
|
||||
while ((parent = get_lock_parent(child))) {
|
||||
child = parent;
|
||||
depth++;
|
||||
}
|
||||
return depth;
|
||||
}
|
||||
|
|
|
|||
Reference in New Issue