[patch] lockdep: use chain hash on CONFIG_DEBUG_LOCKDEP too

From: Ingo Molnar
Date: Thu Dec 07 2006 - 04:33:35 EST


Subject: [patch] lockdep: use chain hash on CONFIG_DEBUG_LOCKDEP too
From: Ingo Molnar <mingo@xxxxxxx>

CONFIG_DEBUG_LOCKDEP is unacceptably slow because it does not utilize
the chain-hash. Turn the chain-hash back on in this case too.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/lockdep.c | 8 --------
1 file changed, 8 deletions(-)

Index: linux/kernel/lockdep.c
===================================================================
--- linux.orig/kernel/lockdep.c
+++ linux/kernel/lockdep.c
@@ -1278,14 +1278,6 @@ static inline int lookup_chain_cache(u64
if (chain->chain_key == chain_key) {
cache_hit:
debug_atomic_inc(&chain_lookup_hits);
- /*
- * In the debugging case, force redundant checking
- * by returning 1:
- */
-#ifdef CONFIG_DEBUG_LOCKDEP
- __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;
-
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