From fb1c8f93d869b34cacb8b8932e2b83d96a19d720 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 10 Sep 2005 00:25:56 -0700 Subject: [PATCH] spinlock consolidation This patch (written by me and also containing many suggestions of Arjan van de Ven) does a major cleanup of the spinlock code. It does the following things: - consolidates and enhances the spinlock/rwlock debugging code - simplifies the asm/spinlock.h files - encapsulates the raw spinlock type and moves generic spinlock features (such as ->break_lock) into the generic code. - cleans up the spinlock code hierarchy to get rid of the spaghetti. Most notably there's now only a single variant of the debugging code, located in lib/spinlock_debug.c. (previously we had one SMP debugging variant per architecture, plus a separate generic one for UP builds) Also, i've enhanced the rwlock debugging facility, it will now track write-owners. There is new spinlock-owner/CPU-tracking on SMP builds too. All locks have lockup detection now, which will work for both soft and hard spin/rwlock lockups. The arch-level include files now only contain the minimally necessary subset of the spinlock code - all the rest that can be generalized now lives in the generic headers: include/asm-i386/spinlock_types.h | 16 include/asm-x86_64/spinlock_types.h | 16 I have also split up the various spinlock variants into separate files, making it easier to see which does what. The new layout is: SMP | UP ----------------------------|----------------------------------- asm/spinlock_types_smp.h | linux/spinlock_types_up.h linux/spinlock_types.h | linux/spinlock_types.h asm/spinlock_smp.h | linux/spinlock_up.h linux/spinlock_api_smp.h | linux/spinlock_api_up.h linux/spinlock.h | linux/spinlock.h /* * here's the role of the various spinlock/rwlock related include files: * * on SMP builds: * * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the * initializers * * linux/spinlock_types.h: * defines the generic type and initializers * * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel * implementations, mostly inline assembly code * * (also included on UP-debug builds:) * * linux/spinlock_api_smp.h: * contains the prototypes for the _spin_*() APIs. * * linux/spinlock.h: builds the final spin_*() APIs. * * on UP builds: * * linux/spinlock_type_up.h: * contains the generic, simplified UP spinlock type. * (which is an empty structure on non-debug builds) * * linux/spinlock_types.h: * defines the generic type and initializers * * linux/spinlock_up.h: * contains the __raw_spin_*()/etc. version of UP * builds. (which are NOPs on non-debug, non-preempt * builds) * * (included on UP-non-debug builds:) * * linux/spinlock_api_up.h: * builds the _spin_*() APIs. * * linux/spinlock.h: builds the final spin_*() APIs. */ All SMP and UP architectures are converted by this patch. arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via crosscompilers. m32r, mips, sh, sparc, have not been tested yet, but should be mostly fine. From: Grant Grundler Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU). Builds 32-bit SMP kernel (not booted or tested). I did not try to build non-SMP kernels. That should be trivial to fix up later if necessary. I converted bit ops atomic_hash lock to raw_spinlock_t. Doing so avoids some ugly nesting of linux/*.h and asm/*.h files. Those particular locks are well tested and contained entirely inside arch specific code. I do NOT expect any new issues to arise with them. If someone does ever need to use debug/metrics with them, then they will need to unravel this hairball between spinlocks, atomic ops, and bit ops that exist only because parisc has exactly one atomic instruction: LDCW (load and clear word). From: "Luck, Tony" ia64 fix Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Grant Grundler Cc: Matthew Wilcox Signed-off-by: Hirokazu Takata Signed-off-by: Mikael Pettersson Signed-off-by: Benoit Boissinot Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-alpha/spinlock.h | 96 +++++++++++--------------------------- include/asm-alpha/spinlock_types.h | 20 ++++++++ 2 files changed, 47 insertions(+), 69 deletions(-) create mode 100644 include/asm-alpha/spinlock_types.h (limited to 'include/asm-alpha') diff --git a/include/asm-alpha/spinlock.h b/include/asm-alpha/spinlock.h index 80780dba998..8197c69eff4 100644 --- a/include/asm-alpha/spinlock.h +++ b/include/asm-alpha/spinlock.h @@ -6,7 +6,6 @@ #include #include - /* * Simple spin lock operations. There are two variants, one clears IRQ's * on the local processor, one does not. @@ -14,43 +13,18 @@ * We make no fairness assumptions. They have a cost. */ -typedef struct { - volatile unsigned int lock; -#ifdef CONFIG_DEBUG_SPINLOCK - int on_cpu; - int line_no; - void *previous; - struct task_struct * task; - const char *base_file; -#endif -} spinlock_t; - -#ifdef CONFIG_DEBUG_SPINLOCK -#define SPIN_LOCK_UNLOCKED (spinlock_t){ 0, -1, 0, NULL, NULL, NULL } -#else -#define SPIN_LOCK_UNLOCKED (spinlock_t){ 0 } -#endif - -#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0) -#define spin_is_locked(x) ((x)->lock != 0) -#define spin_unlock_wait(x) do { barrier(); } while ((x)->lock) - -#ifdef CONFIG_DEBUG_SPINLOCK -extern void _raw_spin_unlock(spinlock_t * lock); -extern void debug_spin_lock(spinlock_t * lock, const char *, int); -extern int debug_spin_trylock(spinlock_t * lock, const char *, int); -#define _raw_spin_lock(LOCK) \ - debug_spin_lock(LOCK, __BASE_FILE__, __LINE__) -#define _raw_spin_trylock(LOCK) \ - debug_spin_trylock(LOCK, __BASE_FILE__, __LINE__) -#else -static inline void _raw_spin_unlock(spinlock_t * lock) +#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) +#define __raw_spin_is_locked(x) ((x)->lock != 0) +#define __raw_spin_unlock_wait(x) \ + do { cpu_relax(); } while ((x)->lock) + +static inline void __raw_spin_unlock(raw_spinlock_t * lock) { mb(); lock->lock = 0; } -static inline void _raw_spin_lock(spinlock_t * lock) +static inline void __raw_spin_lock(raw_spinlock_t * lock) { long tmp; @@ -70,80 +44,64 @@ static inline void _raw_spin_lock(spinlock_t * lock) : "m"(lock->lock) : "memory"); } -static inline int _raw_spin_trylock(spinlock_t *lock) +static inline int __raw_spin_trylock(raw_spinlock_t *lock) { return !test_and_set_bit(0, &lock->lock); } -#endif /* CONFIG_DEBUG_SPINLOCK */ - -#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) /***********************************************************/ -typedef struct { - volatile unsigned int lock; -} rwlock_t; - -#define RW_LOCK_UNLOCKED (rwlock_t){ 0 } - -#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) - -static inline int read_can_lock(rwlock_t *lock) +static inline int __raw_read_can_lock(raw_rwlock_t *lock) { return (lock->lock & 1) == 0; } -static inline int write_can_lock(rwlock_t *lock) +static inline int __raw_write_can_lock(raw_rwlock_t *lock) { return lock->lock == 0; } -#ifdef CONFIG_DEBUG_RWLOCK -extern void _raw_write_lock(rwlock_t * lock); -extern void _raw_read_lock(rwlock_t * lock); -#else -static inline void _raw_write_lock(rwlock_t * lock) +static inline void __raw_read_lock(raw_rwlock_t *lock) { long regx; __asm__ __volatile__( "1: ldl_l %1,%0\n" - " bne %1,6f\n" - " lda %1,1\n" + " blbs %1,6f\n" + " subl %1,2,%1\n" " stl_c %1,%0\n" " beq %1,6f\n" " mb\n" ".subsection 2\n" "6: ldl %1,%0\n" - " bne %1,6b\n" + " blbs %1,6b\n" " br 1b\n" ".previous" : "=m" (*lock), "=&r" (regx) : "m" (*lock) : "memory"); } -static inline void _raw_read_lock(rwlock_t * lock) +static inline void __raw_write_lock(raw_rwlock_t *lock) { long regx; __asm__ __volatile__( "1: ldl_l %1,%0\n" - " blbs %1,6f\n" - " subl %1,2,%1\n" + " bne %1,6f\n" + " lda %1,1\n" " stl_c %1,%0\n" " beq %1,6f\n" " mb\n" ".subsection 2\n" "6: ldl %1,%0\n" - " blbs %1,6b\n" + " bne %1,6b\n" " br 1b\n" ".previous" : "=m" (*lock), "=&r" (regx) : "m" (*lock) : "memory"); } -#endif /* CONFIG_DEBUG_RWLOCK */ -static inline int _raw_read_trylock(rwlock_t * lock) +static inline int __raw_read_trylock(raw_rwlock_t * lock) { long regx; int success; @@ -165,7 +123,7 @@ static inline int _raw_read_trylock(rwlock_t * lock) return success; } -static inline int _raw_write_trylock(rwlock_t * lock) +static inline int __raw_write_trylock(raw_rwlock_t * lock) { long regx; int success; @@ -187,13 +145,7 @@ static inline int _raw_write_trylock(rwlock_t * lock) return success; } -static inline void _raw_write_unlock(rwlock_t * lock) -{ - mb(); - lock->lock = 0; -} - -static inline void _raw_read_unlock(rwlock_t * lock) +static inline void __raw_read_unlock(raw_rwlock_t * lock) { long regx; __asm__ __volatile__( @@ -209,4 +161,10 @@ static inline void _raw_read_unlock(rwlock_t * lock) : "m" (*lock) : "memory"); } +static inline void __raw_write_unlock(raw_rwlock_t * lock) +{ + mb(); + lock->lock = 0; +} + #endif /* _ALPHA_SPINLOCK_H */ diff --git a/include/asm-alpha/spinlock_types.h b/include/asm-alpha/spinlock_types.h new file mode 100644 index 00000000000..8141eb5ebf0 --- /dev/null +++ b/include/asm-alpha/spinlock_types.h @@ -0,0 +1,20 @@ +#ifndef _ALPHA_SPINLOCK_TYPES_H +#define _ALPHA_SPINLOCK_TYPES_H + +#ifndef __LINUX_SPINLOCK_TYPES_H +# error "please don't include this file directly" +#endif + +typedef struct { + volatile unsigned int lock; +} raw_spinlock_t; + +#define __RAW_SPIN_LOCK_UNLOCKED { 0 } + +typedef struct { + volatile unsigned int lock; +} raw_rwlock_t; + +#define __RAW_RW_LOCK_UNLOCKED { 0 } + +#endif -- cgit v1.2.3