From: Ingo Molnar <mingo@elte.hu>
Date: Wed, 13 Dec 2006 08:34:42 +0000 (-0800)
Subject: [PATCH] lockdep: use chain hash on CONFIG_DEBUG_LOCKDEP too
X-Git-Tag: v2.6.20-rc1~87
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=27c3b23226fc649de47e4886ccbf994482f388ba;p=linux-2.6

[PATCH] lockdep: use chain hash on CONFIG_DEBUG_LOCKDEP too

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@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index c4ffd3c1de..69e92c6b04 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1276,14 +1276,6 @@ static inline int lookup_chain_cache(u64 chain_key, struct lock_class *class)
 		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;