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lockdep: shrink held_lock structure 

struct held_lock {
        u64                        prev_chain_key;       /*     0     8 */
        struct lock_class *        class;                /*     8     8 */
        long unsigned int          acquire_ip;           /*    16     8 */
        struct lockdep_map *       instance;             /*    24     8 */
        int                        irq_context;          /*    32     4 */
        int                        trylock;              /*    36     4 */
        int                        read;                 /*    40     4 */
        int                        check;                /*    44     4 */
        int                        hardirqs_off;         /*    48     4 */

        /* size: 56, cachelines: 1 */
        /* padding: 4 */
        /* last cacheline: 56 bytes */
};

struct held_lock {
        u64                        prev_chain_key;       /*     0     8 */
        long unsigned int          acquire_ip;           /*     8     8 */
        struct lockdep_map *       instance;             /*    16     8 */
        unsigned int               class_idx:11;         /*    24:21  4 */
        unsigned int               irq_context:2;        /*    24:19  4 */
        unsigned int               trylock:1;            /*    24:18  4 */
        unsigned int               read:2;               /*    24:16  4 */
        unsigned int               check:2;              /*    24:14  4 */
        unsigned int               hardirqs_off:1;       /*    24:13  4 */

        /* size: 32, cachelines: 1 */
        /* padding: 4 */
        /* bit_padding: 13 bits */
        /* last cacheline: 32 bytes */
};

[mingo@elte.hu: shrunk hlock->class too]
[peterz@infradead.org: fixup bit sizes]
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
This commit is contained in:
Dave Jones 2008-08-11 09:30:23 +02:00 committed by Ingo Molnar
parent 1b12bbc747
commit f82b217e35
3 changed files with 74 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
include/linux/lockdep.h
View File

@ -190,6 +190,9 @@ struct lock_chain {
u64 chain_key;
};
#define MAX_LOCKDEP_KEYS_BITS 11
#define MAX_LOCKDEP_KEYS (1UL << MAX_LOCKDEP_KEYS_BITS)
struct held_lock {
/*
* One-way hash of the dependency chain up to this point. We
@ -206,14 +209,13 @@ struct held_lock {
* with zero), here we store the previous hash value:
*/
u64 prev_chain_key;
struct lock_class *class;
unsigned long acquire_ip;
struct lockdep_map *instance;
#ifdef CONFIG_LOCK_STAT
u64 waittime_stamp;
u64 holdtime_stamp;
#endif
unsigned int class_idx:MAX_LOCKDEP_KEYS_BITS;
/*
* The lock-stack is unified in that the lock chains of interrupt
* contexts nest ontop of process context chains, but we 'separate'
@ -227,11 +229,11 @@ struct held_lock {
* The following field is used to detect when we cross into an
* interrupt context:
*/
int irq_context;
int trylock;
int read;
int check;
int hardirqs_off;
unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
unsigned int trylock:1;
unsigned int read:2; /* see lock_acquire() comment */
unsigned int check:2; /* see lock_acquire() comment */
unsigned int hardirqs_off:1;
};
/*

113
kernel/lockdep.c
View File

@ -124,6 +124,15 @@ static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
unsigned long nr_lock_classes;
static struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
static inline struct lock_class *hlock_class(struct held_lock *hlock)
{
if (!hlock->class_idx) {
DEBUG_LOCKS_WARN_ON(1);
return NULL;
}
return lock_classes + hlock->class_idx - 1;
}
#ifdef CONFIG_LOCK_STAT
static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
@ -222,7 +231,7 @@ static void lock_release_holdtime(struct held_lock *hlock)
holdtime = sched_clock() - hlock->holdtime_stamp;
stats = get_lock_stats(hlock->class);
stats = get_lock_stats(hlock_class(hlock));
if (hlock->read)
lock_time_inc(&stats->read_holdtime, holdtime);
else
@ -518,7 +527,7 @@ static void print_lockdep_cache(struct lockdep_map *lock)
static void print_lock(struct held_lock *hlock)
{
print_lock_name(hlock->class);
print_lock_name(hlock_class(hlock));
printk(", at: ");
print_ip_sym(hlock->acquire_ip);
}
@ -948,7 +957,7 @@ static noinline int print_circular_bug_tail(void)
if (debug_locks_silent)
return 0;
this.class = check_source->class;
this.class = hlock_class(check_source);
if (!save_trace(&this.trace))
return 0;
@ -1057,7 +1066,7 @@ check_noncircular(struct lock_class *source, unsigned int depth)
* Check this lock's dependency list:
*/
list_for_each_entry(entry, &source->locks_after, entry) {
if (entry->class == check_target->class)
if (entry->class == hlock_class(check_target))
return print_circular_bug_header(entry, depth+1);
debug_atomic_inc(&nr_cyclic_checks);
if (!check_noncircular(entry->class, depth+1))
@ -1150,6 +1159,11 @@ find_usage_backwards(struct lock_class *source, unsigned int depth)
return 2;
}
if (!source && debug_locks_off_graph_unlock()) {
WARN_ON(1);
return 0;
}
/*
* Check this lock's dependency list:
*/
@ -1189,9 +1203,9 @@ print_bad_irq_dependency(struct task_struct *curr,
printk("\nand this task is already holding:\n");
print_lock(prev);
printk("which would create a new lock dependency:\n");
print_lock_name(prev->class);
print_lock_name(hlock_class(prev));
printk(" ->");
print_lock_name(next->class);
print_lock_name(hlock_class(next));
printk("\n");
printk("\nbut this new dependency connects a %s-irq-safe lock:\n",
@ -1232,12 +1246,12 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
find_usage_bit = bit_backwards;
/* fills in <backwards_match> */
ret = find_usage_backwards(prev->class, 0);
ret = find_usage_backwards(hlock_class(prev), 0);
if (!ret || ret == 1)
return ret;
find_usage_bit = bit_forwards;
ret = find_usage_forwards(next->class, 0);
ret = find_usage_forwards(hlock_class(next), 0);
if (!ret || ret == 1)
return ret;
/* ret == 2 */
@ -1362,7 +1376,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next,
for (i = 0; i < curr->lockdep_depth; i++) {
prev = curr->held_locks + i;
if (prev->class != next->class)
if (hlock_class(prev) != hlock_class(next))
continue;
/*
* Allow read-after-read recursion of the same
@ -1415,7 +1429,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
*/
check_source = next;
check_target = prev;
if (!(check_noncircular(next->class, 0)))
if (!(check_noncircular(hlock_class(next), 0)))
return print_circular_bug_tail();
if (!check_prev_add_irq(curr, prev, next))
@ -1439,8 +1453,8 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
* chains - the second one will be new, but L1 already has
* L2 added to its dependency list, due to the first chain.)
*/
list_for_each_entry(entry, &prev->class->locks_after, entry) {
if (entry->class == next->class) {
list_for_each_entry(entry, &hlock_class(prev)->locks_after, entry) {
if (entry->class == hlock_class(next)) {
if (distance == 1)
entry->distance = 1;
return 2;
@ -1451,26 +1465,28 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
* Ok, all validations passed, add the new lock
* to the previous lock's dependency list:
*/
ret = add_lock_to_list(prev->class, next->class,
&prev->class->locks_after, next->acquire_ip, distance);
ret = add_lock_to_list(hlock_class(prev), hlock_class(next),
&hlock_class(prev)->locks_after,
next->acquire_ip, distance);
if (!ret)
return 0;
ret = add_lock_to_list(next->class, prev->class,
&next->class->locks_before, next->acquire_ip, distance);
ret = add_lock_to_list(hlock_class(next), hlock_class(prev),
&hlock_class(next)->locks_before,
next->acquire_ip, distance);
if (!ret)
return 0;
/*
* Debugging printouts:
*/
if (verbose(prev->class) || verbose(next->class)) {
if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) {
graph_unlock();
printk("\n new dependency: ");
print_lock_name(prev->class);
print_lock_name(hlock_class(prev));
printk(" => ");
print_lock_name(next->class);
print_lock_name(hlock_class(next));
printk("\n");
dump_stack();
return graph_lock();
@ -1567,7 +1583,7 @@ static inline int lookup_chain_cache(struct task_struct *curr,
struct held_lock *hlock,
u64 chain_key)
{
struct lock_class *class = hlock->class;
struct lock_class *class = hlock_class(hlock);
struct list_head *hash_head = chainhashentry(chain_key);
struct lock_chain *chain;
struct held_lock *hlock_curr, *hlock_next;
@ -1640,7 +1656,7 @@ cache_hit:
if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
chain->base = cn;
for (j = 0; j < chain->depth - 1; j++, i++) {
int lock_id = curr->held_locks[i].class - lock_classes;
int lock_id = curr->held_locks[i].class_idx - 1;
chain_hlocks[chain->base + j] = lock_id;
}
chain_hlocks[chain->base + j] = class - lock_classes;
@ -1736,7 +1752,7 @@ static void check_chain_key(struct task_struct *curr)
WARN_ON(1);
return;
}
id = hlock->class - lock_classes;
id = hlock->class_idx - 1;
if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
return;
@ -1781,7 +1797,7 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
print_lock(this);
printk("{%s} state was registered at:\n", usage_str[prev_bit]);
print_stack_trace(this->class->usage_traces + prev_bit, 1);
print_stack_trace(hlock_class(this)->usage_traces + prev_bit, 1);
print_irqtrace_events(curr);
printk("\nother info that might help us debug this:\n");
@ -1800,7 +1816,7 @@ static inline int
valid_state(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
{
if (unlikely(this->class->usage_mask & (1 << bad_bit)))
if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit)))
return print_usage_bug(curr, this, bad_bit, new_bit);
return 1;
}
@ -1839,7 +1855,7 @@ print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other,
lockdep_print_held_locks(curr);
printk("\nthe first lock's dependencies:\n");
print_lock_dependencies(this->class, 0);
print_lock_dependencies(hlock_class(this), 0);
printk("\nthe second lock's dependencies:\n");
print_lock_dependencies(other, 0);
@ -1862,7 +1878,7 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this,
find_usage_bit = bit;
/* fills in <forwards_match> */
ret = find_usage_forwards(this->class, 0);
ret = find_usage_forwards(hlock_class(this), 0);
if (!ret || ret == 1)
return ret;
@ -1881,7 +1897,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
find_usage_bit = bit;
/* fills in <backwards_match> */
ret = find_usage_backwards(this->class, 0);
ret = find_usage_backwards(hlock_class(this), 0);
if (!ret || ret == 1)
return ret;
@ -1947,7 +1963,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
LOCK_ENABLED_HARDIRQS_READ, "hard-read"))
return 0;
#endif
if (hardirq_verbose(this->class))
if (hardirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_USED_IN_SOFTIRQ:
@ -1972,7 +1988,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
LOCK_ENABLED_SOFTIRQS_READ, "soft-read"))
return 0;
#endif
if (softirq_verbose(this->class))
if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_USED_IN_HARDIRQ_READ:
@ -1985,7 +2001,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
if (!check_usage_forwards(curr, this,
LOCK_ENABLED_HARDIRQS, "hard"))
return 0;
if (hardirq_verbose(this->class))
if (hardirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_USED_IN_SOFTIRQ_READ:
@ -1998,7 +2014,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
if (!check_usage_forwards(curr, this,
LOCK_ENABLED_SOFTIRQS, "soft"))
return 0;
if (softirq_verbose(this->class))
if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_ENABLED_HARDIRQS:
@ -2024,7 +2040,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
LOCK_USED_IN_HARDIRQ_READ, "hard-read"))
return 0;
#endif
if (hardirq_verbose(this->class))
if (hardirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_ENABLED_SOFTIRQS:
@ -2050,7 +2066,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
LOCK_USED_IN_SOFTIRQ_READ, "soft-read"))
return 0;
#endif
if (softirq_verbose(this->class))
if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_ENABLED_HARDIRQS_READ:
@ -2065,7 +2081,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
LOCK_USED_IN_HARDIRQ, "hard"))
return 0;
#endif
if (hardirq_verbose(this->class))
if (hardirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_ENABLED_SOFTIRQS_READ:
@ -2080,7 +2096,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
LOCK_USED_IN_SOFTIRQ, "soft"))
return 0;
#endif
if (softirq_verbose(this->class))
if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
default:
@ -2396,7 +2412,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
* If already set then do not dirty the cacheline,
* nor do any checks:
*/
if (likely(this->class->usage_mask & new_mask))
if (likely(hlock_class(this)->usage_mask & new_mask))
return 1;
if (!graph_lock())
@ -2404,14 +2420,14 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
/*
* Make sure we didnt race:
*/
if (unlikely(this->class->usage_mask & new_mask)) {
if (unlikely(hlock_class(this)->usage_mask & new_mask)) {
graph_unlock();
return 1;
}
this->class->usage_mask |= new_mask;
hlock_class(this)->usage_mask |= new_mask;
if (!save_trace(this->class->usage_traces + new_bit))
if (!save_trace(hlock_class(this)->usage_traces + new_bit))
return 0;
switch (new_bit) {
@ -2545,8 +2561,9 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
return 0;
hlock = curr->held_locks + depth;
hlock->class = class;
if (DEBUG_LOCKS_WARN_ON(!class))
return 0;
hlock->class_idx = class - lock_classes + 1;
hlock->acquire_ip = ip;
hlock->instance = lock;
hlock->trylock = trylock;
@ -2690,7 +2707,7 @@ __lock_set_subclass(struct lockdep_map *lock,
found_it:
class = register_lock_class(lock, subclass, 0);
hlock->class = class;
hlock->class_idx = class - lock_classes + 1;
curr->lockdep_depth = i;
curr->curr_chain_key = hlock->prev_chain_key;
@ -2698,7 +2715,7 @@ found_it:
for (; i < depth; i++) {
hlock = curr->held_locks + i;
if (!__lock_acquire(hlock->instance,
hlock->class->subclass, hlock->trylock,
hlock_class(hlock)->subclass, hlock->trylock,
hlock->read, hlock->check, hlock->hardirqs_off,
hlock->acquire_ip))
return 0;
@ -2759,7 +2776,7 @@ found_it:
for (i++; i < depth; i++) {
hlock = curr->held_locks + i;
if (!__lock_acquire(hlock->instance,
hlock->class->subclass, hlock->trylock,
hlock_class(hlock)->subclass, hlock->trylock,
hlock->read, hlock->check, hlock->hardirqs_off,
hlock->acquire_ip))
return 0;
@ -2804,7 +2821,7 @@ static int lock_release_nested(struct task_struct *curr,
#ifdef CONFIG_DEBUG_LOCKDEP
hlock->prev_chain_key = 0;
hlock->class = NULL;
hlock->class_idx = 0;
hlock->acquire_ip = 0;
hlock->irq_context = 0;
#endif
@ -3000,9 +3017,9 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
found_it:
hlock->waittime_stamp = sched_clock();
point = lock_contention_point(hlock->class, ip);
point = lock_contention_point(hlock_class(hlock), ip);
stats = get_lock_stats(hlock->class);
stats = get_lock_stats(hlock_class(hlock));
if (point < ARRAY_SIZE(stats->contention_point))
stats->contention_point[i]++;
if (lock->cpu != smp_processor_id())
@ -3048,7 +3065,7 @@ found_it:
hlock->holdtime_stamp = now;
}
stats = get_lock_stats(hlock->class);
stats = get_lock_stats(hlock_class(hlock));
if (waittime) {
if (hlock->read)
lock_time_inc(&stats->read_waittime, waittime);

3
kernel/lockdep_internals.h
View File

@ -17,9 +17,6 @@
*/
#define MAX_LOCKDEP_ENTRIES 8192UL
#define MAX_LOCKDEP_KEYS_BITS 11
#define MAX_LOCKDEP_KEYS (1UL << MAX_LOCKDEP_KEYS_BITS)
#define MAX_LOCKDEP_CHAINS_BITS 14
#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)