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author | Ingo Molnar <mingo@elte.hu> | 2005-09-10 00:25:56 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-10 10:06:21 -0700 |
commit | fb1c8f93d869b34cacb8b8932e2b83d96a19d720 (patch) | |
tree | a006d078aa02e421a7dc4793c335308204859d36 /include/asm-alpha/spinlock.h | |
parent | 4327edf6b8a7ac7dce144313947995538842d8fd (diff) | |
download | kernel_goldelico_gta04-fb1c8f93d869b34cacb8b8932e2b83d96a19d720.zip kernel_goldelico_gta04-fb1c8f93d869b34cacb8b8932e2b83d96a19d720.tar.gz kernel_goldelico_gta04-fb1c8f93d869b34cacb8b8932e2b83d96a19d720.tar.bz2 |
[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 <grundler@parisc-linux.org>
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" <tony.luck@intel.com>
ia64 fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjanv@infradead.org>
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-alpha/spinlock.h')
-rw-r--r-- | include/asm-alpha/spinlock.h | 96 |
1 files changed, 27 insertions, 69 deletions
diff --git a/include/asm-alpha/spinlock.h b/include/asm-alpha/spinlock.h index 80780db..8197c69 100644 --- a/include/asm-alpha/spinlock.h +++ b/include/asm-alpha/spinlock.h @@ -6,7 +6,6 @@ #include <linux/kernel.h> #include <asm/current.h> - /* * 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 */ |