diff options
| author | Nick Piggin <npiggin@suse.de> | 2008-01-30 15:31:20 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 15:31:20 +0300 |
| commit | 95c354fe9f7d6decc08a92aa26eb233ecc2155bf (patch) | |
| tree | ec9267032ea875e84216cfb20acb2cfc7c62149f /include/linux/spinlock.h | |
| parent | a95d67f87e1a5f1b4429be3ba3bf7b4051657908 (diff) | |
| download | linux-95c354fe9f7d6decc08a92aa26eb233ecc2155bf.tar.xz | |
spinlock: lockbreak cleanup
The break_lock data structure and code for spinlocks is quite nasty.
Not only does it double the size of a spinlock but it changes locking to
a potentially less optimal trylock.
Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a
__raw_spin_is_contended that uses the lock data itself to determine whether
there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is
not set.
Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to
decouple it from the spinlock implementation, and make it typesafe (rwlocks
do not have any need_lockbreak sites -- why do they even get bloated up
with that break_lock then?).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/spinlock.h')
| -rw-r--r-- | include/linux/spinlock.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index c376f3b36c89..124449733c55 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -120,6 +120,12 @@ do { \ #define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock) +#ifdef CONFIG_GENERIC_LOCKBREAK +#define spin_is_contended(lock) ((lock)->break_lock) +#else +#define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock) +#endif + /** * spin_unlock_wait - wait until the spinlock gets unlocked * @lock: the spinlock in question. |