diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-07-05 13:13:03 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-07-05 13:13:03 -0400 |
| commit | 5e66dd6d66ffe758b39b6dcadf2330753ee1159b (patch) | |
| tree | a72cdcff4448e4af9425cc213ddf56ab23e697fe /kernel/futex.c | |
| parent | 026477c1141b67e98e3bd8bdedb7d4b88a3ecd09 (diff) | |
| parent | ca78f6baca863afe2e6a244a0fe94b3a70211d46 (diff) | |
Merge branch 'master' of /home/trondmy/kernel/linux-2.6/
Diffstat (limited to 'kernel/futex.c')
| -rw-r--r-- | kernel/futex.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 15caf93e4a43..1dc98e4dd287 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -607,6 +607,22 @@ static int unlock_futex_pi(u32 __user *uaddr, u32 uval) } /* + * Express the locking dependencies for lockdep: + */ +static inline void +double_lock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) +{ + if (hb1 <= hb2) { + spin_lock(&hb1->lock); + if (hb1 < hb2) + spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING); + } else { /* hb1 > hb2 */ + spin_lock(&hb2->lock); + spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING); + } +} + +/* * Wake up all waiters hashed on the physical page that is mapped * to this virtual address: */ @@ -674,11 +690,7 @@ retryfull: hb2 = hash_futex(&key2); retry: - if (hb1 < hb2) - spin_lock(&hb1->lock); - spin_lock(&hb2->lock); - if (hb1 > hb2) - spin_lock(&hb1->lock); + double_lock_hb(hb1, hb2); op_ret = futex_atomic_op_inuser(op, uaddr2); if (unlikely(op_ret < 0)) { @@ -787,11 +799,7 @@ static int futex_requeue(u32 __user *uaddr1, u32 __user *uaddr2, hb1 = hash_futex(&key1); hb2 = hash_futex(&key2); - if (hb1 < hb2) - spin_lock(&hb1->lock); - spin_lock(&hb2->lock); - if (hb1 > hb2) - spin_lock(&hb1->lock); + double_lock_hb(hb1, hb2); if (likely(cmpval != NULL)) { u32 curval; |