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authorPierre Peiffer <pierre.peiffer@bull.net>2007-05-09 02:35:02 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-09 12:30:55 -0700
commitd0aa7a70bf03b9de9e995ab272293be1f7937822 (patch)
tree194b30b7b8374b946f166996cb99fb95eb3b7819 /include/linux/futex.h
parentc19384b5b296905d4988c7c684ff540a0f9d65be (diff)
downloadop-kernel-dev-d0aa7a70bf03b9de9e995ab272293be1f7937822.zip
op-kernel-dev-d0aa7a70bf03b9de9e995ab272293be1f7937822.tar.gz
futex_requeue_pi optimization
This patch provides the futex_requeue_pi functionality, which allows some threads waiting on a normal futex to be requeued on the wait-queue of a PI-futex. This provides an optimization, already used for (normal) futexes, to be used with the PI-futexes. This optimization is currently used by the glibc in pthread_broadcast, when using "normal" mutexes. With futex_requeue_pi, it can be used with PRIO_INHERIT mutexes too. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/futex.h')
-rw-r--r--include/linux/futex.h9
1 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/futex.h b/include/linux/futex.h
index 34e54f2..1bd8dfc 100644
--- a/include/linux/futex.h
+++ b/include/linux/futex.h
@@ -17,6 +17,7 @@ union ktime;
#define FUTEX_LOCK_PI 6
#define FUTEX_UNLOCK_PI 7
#define FUTEX_TRYLOCK_PI 8
+#define FUTEX_CMP_REQUEUE_PI 9
/*
* Support for robust futexes: the kernel cleans up held futexes at
@@ -85,9 +86,14 @@ struct robust_list_head {
#define FUTEX_OWNER_DIED 0x40000000
/*
+ * Some processes have been requeued on this PI-futex
+ */
+#define FUTEX_WAITER_REQUEUED 0x20000000
+
+/*
* The rest of the robust-futex field is for the TID:
*/
-#define FUTEX_TID_MASK 0x3fffffff
+#define FUTEX_TID_MASK 0x0fffffff
/*
* This limit protects against a deliberately circular list.
@@ -111,6 +117,7 @@ handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi);
* We set bit 0 to indicate if it's an inode-based key.
*/
union futex_key {
+ u32 __user *uaddr;
struct {
unsigned long pgoff;
struct inode *inode;
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