diff options
| author | Huang, Ying <ying.huang@intel.com> | 2008-06-20 16:39:21 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-06-20 12:21:33 +0200 |
| commit | 443cd507ce7f78c6f8742b72736585c031d5a921 (patch) | |
| tree | 256182911b08287661beca1f90455b14cd0b9151 /kernel/lockdep.c | |
| parent | 2429e4ee78e2fa40f82a4572dd21d4f3b4de9325 (diff) | |
| download | lwn-443cd507ce7f78c6f8742b72736585c031d5a921.tar.gz lwn-443cd507ce7f78c6f8742b72736585c031d5a921.zip | |
lockdep: add lock_class information to lock_chain and output it
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>
Diffstat (limited to 'kernel/lockdep.c')
| -rw-r--r-- | kernel/lockdep.c | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 81a4e4a3f087..a796f1f38ac5 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -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: * |