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>
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index a796f1f..7553a28 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1459,7 +1459,7 @@
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 @@
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 @@
}
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;