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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-14 15:50:44 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-14 15:50:44 -0700 |
| commit | fbed0bc0915e2dec7452fc3e66ad03dd2b0c04c7 (patch) | |
| tree | be106a21a694dfdc949ff430ca6bd9eaf56d3a1f /arch/x86/include | |
| parent | d37a14bb5fed13a52dada3fa9ef4488ac588b35e (diff) | |
| parent | 38460a2178d225b39ade5ac66586c3733391cf86 (diff) | |
| download | linux-fbed0bc0915e2dec7452fc3e66ad03dd2b0c04c7.tar.bz2 | |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking changes from Ingo Molnar:
"Various updates:
- Futex scalability improvements: remove page lock use for shared
futex get_futex_key(), which speeds up 'perf bench futex hash'
benchmarks by over 40% on a 60-core Westmere. This makes anon-mem
shared futexes perform close to private futexes. (Mel Gorman)
- lockdep hash collision detection and fix (Alfredo Alvarez
Fernandez)
- lockdep testing enhancements (Alfredo Alvarez Fernandez)
- robustify lockdep init by using hlists (Andrew Morton, Andrey
Ryabinin)
- mutex and csd_lock micro-optimizations (Davidlohr Bueso)
- small x86 barriers tweaks (Michael S Tsirkin)
- qspinlock updates (Waiman Long)"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
locking/csd_lock: Use smp_cond_acquire() in csd_lock_wait()
locking/csd_lock: Explicitly inline csd_lock*() helpers
futex: Replace barrier() in unqueue_me() with READ_ONCE()
locking/lockdep: Detect chain_key collisions
locking/lockdep: Prevent chain_key collisions
tools/lib/lockdep: Fix link creation warning
tools/lib/lockdep: Add tests for AA and ABBA locking
tools/lib/lockdep: Add userspace version of READ_ONCE()
tools/lib/lockdep: Fix the build on recent kernels
locking/qspinlock: Move __ARCH_SPIN_LOCK_UNLOCKED to qspinlock_types.h
locking/mutex: Allow next waiter lockless wakeup
locking/pvqspinlock: Enable slowpath locking count tracking
locking/qspinlock: Use smp_cond_acquire() in pending code
locking/pvqspinlock: Move lock stealing count tracking code into pv_queued_spin_steal_lock()
locking/mcs: Fix mcs_spin_lock() ordering
futex: Remove requirement for lock_page() in get_futex_key()
futex: Rename barrier references in ordering guarantees
locking/atomics: Update comment about READ_ONCE() and structures
locking/lockdep: Eliminate lockdep_init()
locking/lockdep: Convert hash tables to hlists
...
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/barrier.h | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index a584e1c50918..bfb28caf97b1 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -6,18 +6,17 @@ /* * Force strict CPU ordering. - * And yes, this is required on UP too when we're talking + * And yes, this might be required on UP too when we're talking * to devices. */ #ifdef CONFIG_X86_32 -/* - * Some non-Intel clones support out of order store. wmb() ceases to be a - * nop for these. - */ -#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2) -#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2) -#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM) +#define mb() asm volatile(ALTERNATIVE("lock; addl $0,0(%%esp)", "mfence", \ + X86_FEATURE_XMM2) ::: "memory", "cc") +#define rmb() asm volatile(ALTERNATIVE("lock; addl $0,0(%%esp)", "lfence", \ + X86_FEATURE_XMM2) ::: "memory", "cc") +#define wmb() asm volatile(ALTERNATIVE("lock; addl $0,0(%%esp)", "sfence", \ + X86_FEATURE_XMM2) ::: "memory", "cc") #else #define mb() asm volatile("mfence":::"memory") #define rmb() asm volatile("lfence":::"memory") |