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authorHuang, Ying <ying.huang@intel.com>2008-06-23 11:20:54 +0800
committerIngo Molnar <mingo@elte.hu>2008-06-24 01:28:20 +0200
commitcd1a28e8457e6ebf72c48d84d4e736307e86436e (patch)
tree09371914495f7e3803016516ba887b593ea64a9b /kernel/lockdep.c
parent443cd507ce7f78c6f8742b72736585c031d5a921 (diff)
lockdep: add lock_class information to lock_chain and output it
It is based on x86/master branch of git-x86 tree, and has been tested on x86_64 platform. ChangeLog: v2: - Enclosing proc file system related code into CONFIG_PROVE_LOCKING. - Fix nr_chain_hlocks update code. 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.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index a796f1f38ac..7553a28b99c 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1459,7 +1459,7 @@ out_bug:
unsigned long nr_lock_chains;
struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
-atomic_t nr_chain_hlocks;
+int nr_chain_hlocks;
static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
@@ -1481,7 +1481,7 @@ static inline int lookup_chain_cache(struct task_struct *curr,
struct list_head *hash_head = chainhashentry(chain_key);
struct lock_chain *chain;
struct held_lock *hlock_curr, *hlock_next;
- int i, j, n;
+ int i, j, n, cn;
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return 0;
@@ -1540,9 +1540,15 @@ cache_hit:
}
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;
+ cn = nr_chain_hlocks;
+ while (cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS) {
+ n = cmpxchg(&nr_chain_hlocks, cn, cn + chain->depth);
+ if (n == cn)
+ break;
+ cn = n;
+ }
+ if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
+ chain->base = cn;
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;