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authorLinus Torvalds <torvalds@linux-foundation.org>2014-06-12 18:48:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-12 18:48:15 -0700
commitc29deef32e3699e40da3e9e82267610de04e6b54 (patch)
tree820ab21fe399225f7341499e461ee793a180d414 /arch
parentf9da455b93f6ba076935b4ef4589f61e529ae046 (diff)
parentbd01ec1a13f9a327950c8e3080096446c7804753 (diff)
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more locking changes from Ingo Molnar: "This is the second round of locking tree updates for v3.16, offering large system scalability improvements: - optimistic spinning for rwsems, from Davidlohr Bueso. - 'qrwlocks' core code and x86 enablement, from Waiman Long and PeterZ" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, locking/rwlocks: Enable qrwlocks on x86 locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks locking/mutexes: Documentation update/rewrite locking/rwsem: Fix checkpatch.pl warnings locking/rwsem: Fix warnings for CONFIG_RWSEM_GENERIC_SPINLOCK locking/rwsem: Support optimistic spinning
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/include/asm/qrwlock.h17
-rw-r--r--arch/x86/include/asm/spinlock.h4
-rw-r--r--arch/x86/include/asm/spinlock_types.h4
4 files changed, 26 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b660088c220d..fcefdda5136d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -121,6 +121,7 @@ config X86
select MODULES_USE_ELF_RELA if X86_64
select CLONE_BACKWARDS if X86_32
select ARCH_USE_BUILTIN_BSWAP
+ select ARCH_USE_QUEUE_RWLOCK
select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
select OLD_SIGACTION if X86_32
select COMPAT_OLD_SIGACTION if IA32_EMULATION
diff --git a/arch/x86/include/asm/qrwlock.h b/arch/x86/include/asm/qrwlock.h
new file mode 100644
index 000000000000..70f46f07f94e
--- /dev/null
+++ b/arch/x86/include/asm/qrwlock.h
@@ -0,0 +1,17 @@
+#ifndef _ASM_X86_QRWLOCK_H
+#define _ASM_X86_QRWLOCK_H
+
+#include <asm-generic/qrwlock_types.h>
+
+#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE)
+#define queue_write_unlock queue_write_unlock
+static inline void queue_write_unlock(struct qrwlock *lock)
+{
+ barrier();
+ ACCESS_ONCE(*(u8 *)&lock->cnts) = 0;
+}
+#endif
+
+#include <asm-generic/qrwlock.h>
+
+#endif /* _ASM_X86_QRWLOCK_H */
diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h
index 0f62f5482d91..54f1c8068c02 100644
--- a/arch/x86/include/asm/spinlock.h
+++ b/arch/x86/include/asm/spinlock.h
@@ -187,6 +187,7 @@ static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
cpu_relax();
}
+#ifndef CONFIG_QUEUE_RWLOCK
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
@@ -269,6 +270,9 @@ static inline void arch_write_unlock(arch_rwlock_t *rw)
asm volatile(LOCK_PREFIX WRITE_LOCK_ADD(%1) "%0"
: "+m" (rw->write) : "i" (RW_LOCK_BIAS) : "memory");
}
+#else
+#include <asm/qrwlock.h>
+#endif /* CONFIG_QUEUE_RWLOCK */
#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
diff --git a/arch/x86/include/asm/spinlock_types.h b/arch/x86/include/asm/spinlock_types.h
index 4f1bea19945b..73c4c007200f 100644
--- a/arch/x86/include/asm/spinlock_types.h
+++ b/arch/x86/include/asm/spinlock_types.h
@@ -34,6 +34,10 @@ typedef struct arch_spinlock {
#define __ARCH_SPIN_LOCK_UNLOCKED { { 0 } }
+#ifdef CONFIG_QUEUE_RWLOCK
+#include <asm-generic/qrwlock_types.h>
+#else
#include <asm/rwlock.h>
+#endif
#endif /* _ASM_X86_SPINLOCK_TYPES_H */