diff --git a/arch/alpha/include/asm/processor.h b/arch/alpha/include/asm/processor.h index 6cb7fe85c4b5..b4cf03690394 100644 --- a/arch/alpha/include/asm/processor.h +++ b/arch/alpha/include/asm/processor.h @@ -57,6 +57,7 @@ unsigned long get_wchan(struct task_struct *p); ((tsk) == current ? rdusp() : task_thread_info(tsk)->pcb.usp) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() #define ARCH_HAS_PREFETCH #define ARCH_HAS_PREFETCHW diff --git a/arch/arc/include/asm/processor.h b/arch/arc/include/asm/processor.h index d99f9b37cd15..82588f3ba77f 100644 --- a/arch/arc/include/asm/processor.h +++ b/arch/arc/include/asm/processor.h @@ -62,6 +62,8 @@ unsigned long thread_saved_pc(struct task_struct *t); #define cpu_relax() do { } while (0) #endif +#define cpu_relax_lowlatency() cpu_relax() + #define copy_segments(tsk, mm) do { } while (0) #define release_segments(mm) do { } while (0) diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index c3d5fc124a05..8a1e8e995dae 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -82,6 +82,8 @@ unsigned long get_wchan(struct task_struct *p); #define cpu_relax() barrier() #endif +#define cpu_relax_lowlatency() cpu_relax() + #define task_pt_regs(p) \ ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1) diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 34de2a8f7d93..4610b0daf1bf 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -129,6 +129,7 @@ extern void release_thread(struct task_struct *); unsigned long get_wchan(struct task_struct *p); #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() /* Thread switching */ extern struct task_struct *cpu_switch_to(struct task_struct *prev, diff --git a/arch/avr32/include/asm/processor.h b/arch/avr32/include/asm/processor.h index 972adcc1e8f4..941593c7d9f3 100644 --- a/arch/avr32/include/asm/processor.h +++ b/arch/avr32/include/asm/processor.h @@ -92,6 +92,7 @@ extern struct avr32_cpuinfo boot_cpu_data; #define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 3)) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() #define cpu_sync_pipeline() asm volatile("sub pc, -2" : : : "memory") struct cpu_context { diff --git a/arch/blackfin/include/asm/processor.h b/arch/blackfin/include/asm/processor.h index d0e72e9475a6..7acd46653df3 100644 --- a/arch/blackfin/include/asm/processor.h +++ b/arch/blackfin/include/asm/processor.h @@ -99,7 +99,7 @@ unsigned long get_wchan(struct task_struct *p); #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) #define cpu_relax() smp_mb() - +#define cpu_relax_lowlatency() cpu_relax() /* Get the Silicon Revision of the chip */ static inline uint32_t __pure bfin_revid(void) diff --git a/arch/c6x/include/asm/processor.h b/arch/c6x/include/asm/processor.h index b9eb3da7f278..f2ef31be2f8b 100644 --- a/arch/c6x/include/asm/processor.h +++ b/arch/c6x/include/asm/processor.h @@ -121,6 +121,7 @@ extern unsigned long get_wchan(struct task_struct *p); #define KSTK_ESP(task) (task_pt_regs(task)->sp) #define cpu_relax() do { } while (0) +#define cpu_relax_lowlatency() cpu_relax() extern const struct seq_operations cpuinfo_op; diff --git a/arch/cris/include/asm/processor.h b/arch/cris/include/asm/processor.h index 15b815df29c1..862126b58116 100644 --- a/arch/cris/include/asm/processor.h +++ b/arch/cris/include/asm/processor.h @@ -63,6 +63,7 @@ static inline void release_thread(struct task_struct *dead_task) #define init_stack (init_thread_union.stack) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() void default_idle(void); diff --git a/arch/hexagon/include/asm/processor.h b/arch/hexagon/include/asm/processor.h index 45a825402f63..d8501137c8d0 100644 --- a/arch/hexagon/include/asm/processor.h +++ b/arch/hexagon/include/asm/processor.h @@ -56,6 +56,7 @@ struct thread_struct { } #define cpu_relax() __vmyield() +#define cpu_relax_lowlatency() cpu_relax() /* * Decides where the kernel will search for a free chunk of vm space during diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h index efd1b927ccb7..c7367130ab14 100644 --- a/arch/ia64/include/asm/processor.h +++ b/arch/ia64/include/asm/processor.h @@ -548,6 +548,7 @@ ia64_eoi (void) } #define cpu_relax() ia64_hint(ia64_hint_pause) +#define cpu_relax_lowlatency() cpu_relax() static inline int ia64_get_irr(unsigned int vector) diff --git a/arch/m32r/include/asm/processor.h b/arch/m32r/include/asm/processor.h index 5767367550c6..9f8fd9bef70f 100644 --- a/arch/m32r/include/asm/processor.h +++ b/arch/m32r/include/asm/processor.h @@ -133,5 +133,6 @@ unsigned long get_wchan(struct task_struct *p); #define KSTK_ESP(tsk) ((tsk)->thread.sp) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() #endif /* _ASM_M32R_PROCESSOR_H */ diff --git a/arch/m68k/include/asm/processor.h b/arch/m68k/include/asm/processor.h index b0768a657920..20dda1d4b860 100644 --- a/arch/m68k/include/asm/processor.h +++ b/arch/m68k/include/asm/processor.h @@ -176,5 +176,6 @@ unsigned long get_wchan(struct task_struct *p); #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0)) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() #endif diff --git a/arch/metag/include/asm/processor.h b/arch/metag/include/asm/processor.h index a8a37477c66e..881071c07942 100644 --- a/arch/metag/include/asm/processor.h +++ b/arch/metag/include/asm/processor.h @@ -155,6 +155,7 @@ unsigned long get_wchan(struct task_struct *p); #define user_stack_pointer(regs) ((regs)->ctx.AX[0].U0) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() extern void setup_priv(void); diff --git a/arch/microblaze/include/asm/processor.h b/arch/microblaze/include/asm/processor.h index 9d31b057c355..497a988d79c2 100644 --- a/arch/microblaze/include/asm/processor.h +++ b/arch/microblaze/include/asm/processor.h @@ -22,6 +22,7 @@ extern const struct seq_operations cpuinfo_op; # define cpu_relax() barrier() +# define cpu_relax_lowlatency() cpu_relax() #define task_pt_regs(tsk) \ (((struct pt_regs *)(THREAD_SIZE + task_stack_page(tsk))) - 1) diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h index ad70cba8daff..d5098bc554f4 100644 --- a/arch/mips/include/asm/processor.h +++ b/arch/mips/include/asm/processor.h @@ -367,6 +367,7 @@ unsigned long get_wchan(struct task_struct *p); #define KSTK_STATUS(tsk) (task_pt_regs(tsk)->cp0_status) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() /* * Return_address is a replacement for __builtin_return_address(count) diff --git a/arch/mn10300/include/asm/processor.h b/arch/mn10300/include/asm/processor.h index 8b80b19d0c8a..769d5ed8e992 100644 --- a/arch/mn10300/include/asm/processor.h +++ b/arch/mn10300/include/asm/processor.h @@ -68,7 +68,9 @@ extern struct mn10300_cpuinfo cpu_data[]; extern void identify_cpu(struct mn10300_cpuinfo *); extern void print_cpu_info(struct mn10300_cpuinfo *); extern void dodgy_tsc(void); + #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() /* * User space process size: 1.75GB (default). diff --git a/arch/openrisc/include/asm/processor.h b/arch/openrisc/include/asm/processor.h index cab746fa9e87..4d235e3d2534 100644 --- a/arch/openrisc/include/asm/processor.h +++ b/arch/openrisc/include/asm/processor.h @@ -101,6 +101,7 @@ extern unsigned long thread_saved_pc(struct task_struct *t); #define init_stack (init_thread_union.stack) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() #endif /* __ASSEMBLY__ */ #endif /* __ASM_OPENRISC_PROCESSOR_H */ diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h index d951c9681ab3..689a8ade3606 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -338,6 +338,7 @@ extern unsigned long get_wchan(struct task_struct *p); #define KSTK_ESP(tsk) ((tsk)->thread.regs.gr[30]) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() /* Used as a macro to identify the combined VIPT/PIPT cached * CPUs which require a guarantee of coherency (no inequivalent diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 6d59072e13a7..dda7ac4c80bd 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -400,6 +400,8 @@ static inline unsigned long __pack_fe01(unsigned int fpmode) #define cpu_relax() barrier() #endif +#define cpu_relax_lowlatency() cpu_relax() + /* Check that a certain kernel stack pointer is valid in task_struct p */ int validate_sp(unsigned long sp, struct task_struct *p, unsigned long nbytes); diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 6f02d452bbee..e568fc8a7250 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -217,7 +217,7 @@ static inline void cpu_relax(void) barrier(); } -#define arch_mutex_cpu_relax() barrier() +#define cpu_relax_lowlatency() barrier() static inline void psw_set_key(unsigned int key) { diff --git a/arch/score/include/asm/processor.h b/arch/score/include/asm/processor.h index d9a922d8711b..851f441991d2 100644 --- a/arch/score/include/asm/processor.h +++ b/arch/score/include/asm/processor.h @@ -24,6 +24,7 @@ extern unsigned long get_wchan(struct task_struct *p); #define current_text_addr() ({ __label__ _l; _l: &&_l; }) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() #define release_thread(thread) do {} while (0) /* diff --git a/arch/sh/include/asm/processor.h b/arch/sh/include/asm/processor.h index 5448f9bbf4ab..1506897648aa 100644 --- a/arch/sh/include/asm/processor.h +++ b/arch/sh/include/asm/processor.h @@ -97,6 +97,7 @@ extern struct sh_cpuinfo cpu_data[]; #define cpu_sleep() __asm__ __volatile__ ("sleep" : : : "memory") #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() void default_idle(void); void stop_this_cpu(void *); diff --git a/arch/sparc/include/asm/processor_32.h b/arch/sparc/include/asm/processor_32.h index a564817bbc2e..812fd08f3e62 100644 --- a/arch/sparc/include/asm/processor_32.h +++ b/arch/sparc/include/asm/processor_32.h @@ -119,6 +119,8 @@ extern struct task_struct *last_task_used_math; int do_mathemu(struct pt_regs *regs, struct task_struct *fpt); #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() + extern void (*sparc_idle)(void); #endif diff --git a/arch/sparc/include/asm/processor_64.h b/arch/sparc/include/asm/processor_64.h index 7028fe1a7c04..6924bdefe148 100644 --- a/arch/sparc/include/asm/processor_64.h +++ b/arch/sparc/include/asm/processor_64.h @@ -216,6 +216,7 @@ unsigned long get_wchan(struct task_struct *task); "nop\n\t" \ ".previous" \ ::: "memory") +#define cpu_relax_lowlatency() cpu_relax() /* Prefetch support. This is tuned for UltraSPARC-III and later. * UltraSPARC-I will treat these as nops, and UltraSPARC-II has diff --git a/arch/tile/include/asm/processor.h b/arch/tile/include/asm/processor.h index 42323636c459..dd4f9f17e30a 100644 --- a/arch/tile/include/asm/processor.h +++ b/arch/tile/include/asm/processor.h @@ -266,6 +266,8 @@ static inline void cpu_relax(void) barrier(); } +#define cpu_relax_lowlatency() cpu_relax() + /* Info on this processor (see fs/proc/cpuinfo.c) */ struct seq_operations; extern const struct seq_operations cpuinfo_op; diff --git a/arch/unicore32/include/asm/processor.h b/arch/unicore32/include/asm/processor.h index 4eaa42167667..8d21b7adf26b 100644 --- a/arch/unicore32/include/asm/processor.h +++ b/arch/unicore32/include/asm/processor.h @@ -71,6 +71,7 @@ extern void release_thread(struct task_struct *); unsigned long get_wchan(struct task_struct *p); #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() #define task_pt_regs(p) \ ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index a4ea02351f4d..32cc237f8e20 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -696,6 +696,8 @@ static inline void cpu_relax(void) rep_nop(); } +#define cpu_relax_lowlatency() cpu_relax() + /* Stop speculative execution and prefetching of modified code. */ static inline void sync_core(void) { diff --git a/arch/x86/um/asm/processor.h b/arch/x86/um/asm/processor.h index 04f82e020f2b..2a206d2b14ab 100644 --- a/arch/x86/um/asm/processor.h +++ b/arch/x86/um/asm/processor.h @@ -25,7 +25,8 @@ static inline void rep_nop(void) __asm__ __volatile__("rep;nop": : :"memory"); } -#define cpu_relax() rep_nop() +#define cpu_relax() rep_nop() +#define cpu_relax_lowlatency() cpu_relax() #include diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h index abb59708a3b7..b61bdf0eea25 100644 --- a/arch/xtensa/include/asm/processor.h +++ b/arch/xtensa/include/asm/processor.h @@ -182,6 +182,7 @@ extern unsigned long get_wchan(struct task_struct *p); #define KSTK_ESP(tsk) (task_pt_regs(tsk)->areg[1]) #define cpu_relax() barrier() +#define cpu_relax_lowlatency() cpu_relax() /* Special register access. */ diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 42aa9b9ecd5f..8d5535c58cc2 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -176,8 +176,4 @@ extern void mutex_unlock(struct mutex *lock); extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); -#ifndef arch_mutex_cpu_relax -# define arch_mutex_cpu_relax() cpu_relax() -#endif - #endif /* __LINUX_MUTEX_H */ diff --git a/kernel/locking/mcs_spinlock.c b/kernel/locking/mcs_spinlock.c index be9ee1559fca..9887a905a762 100644 --- a/kernel/locking/mcs_spinlock.c +++ b/kernel/locking/mcs_spinlock.c @@ -1,6 +1,4 @@ - #include -#include #include #include "mcs_spinlock.h" @@ -79,7 +77,7 @@ osq_wait_next(struct optimistic_spin_queue *lock, break; } - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } return next; @@ -120,7 +118,7 @@ bool osq_lock(struct optimistic_spin_queue *lock) if (need_resched()) goto unqueue; - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } return true; @@ -146,7 +144,7 @@ unqueue: if (smp_load_acquire(&node->locked)) return true; - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); /* * Or we race against a concurrent unqueue()'s step-B, in which diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h index 74356dc0ce29..23e89c5930e9 100644 --- a/kernel/locking/mcs_spinlock.h +++ b/kernel/locking/mcs_spinlock.h @@ -27,7 +27,7 @@ struct mcs_spinlock { #define arch_mcs_spin_lock_contended(l) \ do { \ while (!(smp_load_acquire(l))) \ - arch_mutex_cpu_relax(); \ + cpu_relax_lowlatency(); \ } while (0) #endif @@ -104,7 +104,7 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node) return; /* Wait until the next pointer is set */ while (!(next = ACCESS_ONCE(node->next))) - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } /* Pass lock to next waiter. */ diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index d3100521388c..ae712b25e492 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -146,7 +146,7 @@ int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner) if (need_resched()) break; - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } rcu_read_unlock(); @@ -464,7 +464,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, * memory barriers as we'll eventually observe the right * values at the cost of a few extra spins. */ - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } osq_unlock(&lock->osq); slowpath: diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c index fb5b8ac411a5..f956ede7f90d 100644 --- a/kernel/locking/qrwlock.c +++ b/kernel/locking/qrwlock.c @@ -20,7 +20,6 @@ #include #include #include -#include #include /** @@ -35,7 +34,7 @@ static __always_inline void rspin_until_writer_unlock(struct qrwlock *lock, u32 cnts) { while ((cnts & _QW_WMASK) == _QW_LOCKED) { - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); cnts = smp_load_acquire((u32 *)&lock->cnts); } } @@ -75,7 +74,7 @@ void queue_read_lock_slowpath(struct qrwlock *lock) * to make sure that the write lock isn't taken. */ while (atomic_read(&lock->cnts) & _QW_WMASK) - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); cnts = atomic_add_return(_QR_BIAS, &lock->cnts) - _QR_BIAS; rspin_until_writer_unlock(lock, cnts); @@ -114,7 +113,7 @@ void queue_write_lock_slowpath(struct qrwlock *lock) cnts | _QW_WAITING) == cnts)) break; - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } /* When no more readers, set the locked flag */ @@ -125,7 +124,7 @@ void queue_write_lock_slowpath(struct qrwlock *lock) _QW_LOCKED) == _QW_WAITING)) break; - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } unlock: arch_spin_unlock(&lock->lock); diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index a2391ac135c8..d6203faf2eb1 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -329,7 +329,7 @@ bool rwsem_spin_on_owner(struct rw_semaphore *sem, struct task_struct *owner) if (need_resched()) break; - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } rcu_read_unlock(); @@ -381,7 +381,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem) * memory barriers as we'll eventually observe the right * values at the cost of a few extra spins. */ - arch_mutex_cpu_relax(); + cpu_relax_lowlatency(); } osq_unlock(&sem->osq); done: diff --git a/lib/lockref.c b/lib/lockref.c index f07a40d33871..d2233de9a86e 100644 --- a/lib/lockref.c +++ b/lib/lockref.c @@ -1,6 +1,5 @@ #include #include -#include #if USE_CMPXCHG_LOCKREF @@ -29,7 +28,7 @@ if (likely(old.lock_count == prev.lock_count)) { \ SUCCESS; \ } \ - arch_mutex_cpu_relax(); \ + cpu_relax_lowlatency(); \ } \ } while (0)