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lockdep: add lock_class information to lock_chain and output it

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This patch records array of lock_class into lock_chain, and export
lock_chain information via /proc/lockdep_chains.

It is based on x86/master branch of git-x86 tree, and has been tested
on x86_64 platform.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Huang, Ying
2008-06-20 16:39:21 +08:00
committed by Ingo Molnar
parent 2429e4ee78
commit 443cd507ce
4 changed files with 135 additions and 3 deletions
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38
kernel/lockdep.c
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@ -1458,7 +1458,14 @@ out_bug:
}
unsigned long nr_lock_chains;
static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
atomic_t nr_chain_hlocks;
static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
{
return lock_classes + chain_hlocks[chain->base + i];
}
/*
* Look up a dependency chain. If the key is not present yet then
@ -1466,10 +1473,15 @@ static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
* validated. If the key is already hashed, return 0.
* (On return with 1 graph_lock is held.)
*/
static inline int lookup_chain_cache(u64 chain_key, struct lock_class *class)
static inline int lookup_chain_cache(struct task_struct *curr,
struct held_lock *hlock,
u64 chain_key)
{
struct lock_class *class = hlock->class;
struct list_head *hash_head = chainhashentry(chain_key);
struct lock_chain *chain;
struct held_lock *hlock_curr, *hlock_next;
int i, j, n;
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return 0;
@ -1517,6 +1529,26 @@ cache_hit:
}
chain = lock_chains + nr_lock_chains++;
chain->chain_key = chain_key;
chain->irq_context = hlock->irq_context;
/* Find the first held_lock of current chain */
hlock_next = hlock;
for (i = curr->lockdep_depth - 1; i >= 0; i--) {
hlock_curr = curr->held_locks + i;
if (hlock_curr->irq_context != hlock_next->irq_context)
break;
hlock_next = hlock;
}
i++;
chain->depth = curr->lockdep_depth + 1 - i;
n = atomic_add_return(chain->depth, &nr_chain_hlocks);
if (unlikely(n < MAX_LOCKDEP_CHAIN_HLOCKS)) {
chain->base = n - chain->depth;
for (j = 0; j < chain->depth - 1; j++, i++) {
int lock_id = curr->held_locks[i].class - lock_classes;
chain_hlocks[chain->base + j] = lock_id;
}
chain_hlocks[chain->base + j] = class - lock_classes;
}
list_add_tail_rcu(&chain->entry, hash_head);
debug_atomic_inc(&chain_lookup_misses);
inc_chains();
@ -1538,7 +1570,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
* graph_lock for us)
*/
if (!hlock->trylock && (hlock->check == 2) &&
lookup_chain_cache(chain_key, hlock->class)) {
lookup_chain_cache(curr, hlock, chain_key)) {
/*
* Check whether last held lock:
*