diff options
| author | Ingo Molnar <mingo@elte.hu> | 2006-12-13 00:34:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-13 09:05:50 -0800 |
| commit | 81fc685a898f84d0787eeebb1c118de0bd3484a0 (patch) | |
| tree | f604565b228c12b3db6037673870882c8022c4a9 /kernel/lockdep.c | |
| parent | a664089741aa9010333ecbdadbf5d9de62bafa2d (diff) | |
| download | lwn-81fc685a898f84d0787eeebb1c118de0bd3484a0.tar.gz lwn-81fc685a898f84d0787eeebb1c118de0bd3484a0.zip | |
[PATCH] lockdep: improve verbose messages
Make verbose lockdep messages (off by default) more informative by printing
out the hash chain key. (this patch was what helped me catch the earlier
lockdep hash-collision bug)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/lockdep.c')
| -rw-r--r-- | kernel/lockdep.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 5d69c7d7407e..5ba2825bd46a 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -1264,7 +1264,7 @@ out_unlock_set: * add it and return 0 - in this case the new dependency chain is * validated. If the key is already hashed, return 1. */ -static inline int lookup_chain_cache(u64 chain_key) +static inline int lookup_chain_cache(u64 chain_key, struct lock_class *class) { struct list_head *hash_head = chainhashentry(chain_key); struct lock_chain *chain; @@ -1286,9 +1286,13 @@ cache_hit: __raw_spin_lock(&hash_lock); return 1; #endif + if (very_verbose(class)) + printk("\nhash chain already cached, key: %016Lx tail class: [%p] %s\n", chain_key, class->key, class->name); return 0; } } + if (very_verbose(class)) + printk("\nnew hash chain, key: %016Lx tail class: [%p] %s\n", chain_key, class->key, class->name); /* * Allocate a new chain entry from the static array, and add * it to the hash: @@ -2139,7 +2143,7 @@ out_calc_hash: * (If lookup_chain_cache() returns with 1 it acquires * hash_lock for us) */ - if (!trylock && (check == 2) && lookup_chain_cache(chain_key)) { + if (!trylock && (check == 2) && lookup_chain_cache(chain_key, class)) { /* * Check whether last held lock: * |