diff options
author | Davidlohr Bueso <dave@stgolabs.net> | 2015-01-06 14:45:07 -0500 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2015-01-14 09:07:32 -0500 |
commit | d84b6728c54dcf73bcef3e3f7cf6767e2d224e39 (patch) | |
tree | c3d8f60aee0a71f79666e3d47df73deff975a5ab /kernel/locking | |
parent | 4bd19084faa61a8c68586e74f03f5776179f65c2 (diff) |
locking/mcs: Better differentiate between MCS variants
We have two flavors of the MCS spinlock: standard and cancelable (OSQ).
While each one is independent of the other, we currently mix and match
them. This patch:
- Moves the OSQ code out of mcs_spinlock.h (which only deals with the traditional
version) into include/linux/osq_lock.h. No unnecessary code is added to the
more global header file, anything locks that make use of OSQ must include
it anyway.
- Renames mcs_spinlock.c to osq_lock.c. This file only contains osq code.
- Introduces a CONFIG_LOCK_SPIN_ON_OWNER in order to only build osq_lock
if there is support for it.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1420573509-24774-5-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
-rw-r--r-- | kernel/locking/Makefile | 3 | ||||
-rw-r--r-- | kernel/locking/mcs_spinlock.h | 16 | ||||
-rw-r--r-- | kernel/locking/osq_lock.c (renamed from kernel/locking/mcs_spinlock.c) | 7 |
3 files changed, 3 insertions, 23 deletions
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile index 8541bfdfd232..4ca8eb151975 100644 --- a/kernel/locking/Makefile +++ b/kernel/locking/Makefile | |||
@@ -1,5 +1,5 @@ | |||
1 | 1 | ||
2 | obj-y += mutex.o semaphore.o rwsem.o mcs_spinlock.o | 2 | obj-y += mutex.o semaphore.o rwsem.o |
3 | 3 | ||
4 | ifdef CONFIG_FUNCTION_TRACER | 4 | ifdef CONFIG_FUNCTION_TRACER |
5 | CFLAGS_REMOVE_lockdep.o = -pg | 5 | CFLAGS_REMOVE_lockdep.o = -pg |
@@ -14,6 +14,7 @@ ifeq ($(CONFIG_PROC_FS),y) | |||
14 | obj-$(CONFIG_LOCKDEP) += lockdep_proc.o | 14 | obj-$(CONFIG_LOCKDEP) += lockdep_proc.o |
15 | endif | 15 | endif |
16 | obj-$(CONFIG_SMP) += spinlock.o | 16 | obj-$(CONFIG_SMP) += spinlock.o |
17 | obj-$(CONFIG_LOCK_SPIN_ON_OWNER) += osq_lock.o | ||
17 | obj-$(CONFIG_SMP) += lglock.o | 18 | obj-$(CONFIG_SMP) += lglock.o |
18 | obj-$(CONFIG_PROVE_LOCKING) += spinlock.o | 19 | obj-$(CONFIG_PROVE_LOCKING) += spinlock.o |
19 | obj-$(CONFIG_RT_MUTEXES) += rtmutex.o | 20 | obj-$(CONFIG_RT_MUTEXES) += rtmutex.o |
diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h index 4d60986fcbee..d1fe2ba5bac9 100644 --- a/kernel/locking/mcs_spinlock.h +++ b/kernel/locking/mcs_spinlock.h | |||
@@ -108,20 +108,4 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node) | |||
108 | arch_mcs_spin_unlock_contended(&next->locked); | 108 | arch_mcs_spin_unlock_contended(&next->locked); |
109 | } | 109 | } |
110 | 110 | ||
111 | /* | ||
112 | * Cancellable version of the MCS lock above. | ||
113 | * | ||
114 | * Intended for adaptive spinning of sleeping locks: | ||
115 | * mutex_lock()/rwsem_down_{read,write}() etc. | ||
116 | */ | ||
117 | |||
118 | struct optimistic_spin_node { | ||
119 | struct optimistic_spin_node *next, *prev; | ||
120 | int locked; /* 1 if lock acquired */ | ||
121 | int cpu; /* encoded CPU # value */ | ||
122 | }; | ||
123 | |||
124 | extern bool osq_lock(struct optimistic_spin_queue *lock); | ||
125 | extern void osq_unlock(struct optimistic_spin_queue *lock); | ||
126 | |||
127 | #endif /* __LINUX_MCS_SPINLOCK_H */ | 111 | #endif /* __LINUX_MCS_SPINLOCK_H */ |
diff --git a/kernel/locking/mcs_spinlock.c b/kernel/locking/osq_lock.c index 9887a905a762..ec83d4db8ec6 100644 --- a/kernel/locking/mcs_spinlock.c +++ b/kernel/locking/osq_lock.c | |||
@@ -1,8 +1,6 @@ | |||
1 | #include <linux/percpu.h> | 1 | #include <linux/percpu.h> |
2 | #include <linux/sched.h> | 2 | #include <linux/sched.h> |
3 | #include "mcs_spinlock.h" | 3 | #include <linux/osq_lock.h> |
4 | |||
5 | #ifdef CONFIG_SMP | ||
6 | 4 | ||
7 | /* | 5 | /* |
8 | * An MCS like lock especially tailored for optimistic spinning for sleeping | 6 | * An MCS like lock especially tailored for optimistic spinning for sleeping |
@@ -203,6 +201,3 @@ void osq_unlock(struct optimistic_spin_queue *lock) | |||
203 | if (next) | 201 | if (next) |
204 | ACCESS_ONCE(next->locked) = 1; | 202 | ACCESS_ONCE(next->locked) = 1; |
205 | } | 203 | } |
206 | |||
207 | #endif | ||
208 | |||