[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>
diff --git a/include/asm-sparc64/spinlock.h b/include/asm-sparc64/spinlock.h
index a02c437..ec85d12 100644
--- a/include/asm-sparc64/spinlock.h
+++ b/include/asm-sparc64/spinlock.h
@@ -29,24 +29,13 @@
* must be pre-V9 branches.
*/
-#ifndef CONFIG_DEBUG_SPINLOCK
+#define __raw_spin_is_locked(lp) ((lp)->lock != 0)
-typedef struct {
- volatile unsigned char lock;
-#ifdef CONFIG_PREEMPT
- unsigned int break_lock;
-#endif
-} spinlock_t;
-#define SPIN_LOCK_UNLOCKED (spinlock_t) {0,}
+#define __raw_spin_unlock_wait(lp) \
+ do { rmb(); \
+ } while((lp)->lock)
-#define spin_lock_init(lp) do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0)
-#define spin_is_locked(lp) ((lp)->lock != 0)
-
-#define spin_unlock_wait(lp) \
-do { rmb(); \
-} while((lp)->lock)
-
-static inline void _raw_spin_lock(spinlock_t *lock)
+static inline void __raw_spin_lock(raw_spinlock_t *lock)
{
unsigned long tmp;
@@ -67,7 +56,7 @@
: "memory");
}
-static inline int _raw_spin_trylock(spinlock_t *lock)
+static inline int __raw_spin_trylock(raw_spinlock_t *lock)
{
unsigned long result;
@@ -81,7 +70,7 @@
return (result == 0UL);
}
-static inline void _raw_spin_unlock(spinlock_t *lock)
+static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
__asm__ __volatile__(
" membar #StoreStore | #LoadStore\n"
@@ -91,7 +80,7 @@
: "memory");
}
-static inline void _raw_spin_lock_flags(spinlock_t *lock, unsigned long flags)
+static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
{
unsigned long tmp1, tmp2;
@@ -115,51 +104,9 @@
: "memory");
}
-#else /* !(CONFIG_DEBUG_SPINLOCK) */
-
-typedef struct {
- volatile unsigned char lock;
- unsigned int owner_pc, owner_cpu;
-#ifdef CONFIG_PREEMPT
- unsigned int break_lock;
-#endif
-} spinlock_t;
-#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0, 0xff }
-#define spin_lock_init(lp) do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0)
-#define spin_is_locked(__lock) ((__lock)->lock != 0)
-#define spin_unlock_wait(__lock) \
-do { \
- rmb(); \
-} while((__lock)->lock)
-
-extern void _do_spin_lock(spinlock_t *lock, char *str, unsigned long caller);
-extern void _do_spin_unlock(spinlock_t *lock);
-extern int _do_spin_trylock(spinlock_t *lock, unsigned long caller);
-
-#define _raw_spin_trylock(lp) \
- _do_spin_trylock(lp, (unsigned long) __builtin_return_address(0))
-#define _raw_spin_lock(lock) \
- _do_spin_lock(lock, "spin_lock", \
- (unsigned long) __builtin_return_address(0))
-#define _raw_spin_unlock(lock) _do_spin_unlock(lock)
-#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
-
-#endif /* CONFIG_DEBUG_SPINLOCK */
-
/* Multi-reader locks, these are much saner than the 32-bit Sparc ones... */
-#ifndef CONFIG_DEBUG_SPINLOCK
-
-typedef struct {
- volatile unsigned int lock;
-#ifdef CONFIG_PREEMPT
- unsigned int break_lock;
-#endif
-} rwlock_t;
-#define RW_LOCK_UNLOCKED (rwlock_t) {0,}
-#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
-
-static void inline __read_lock(rwlock_t *lock)
+static void inline __read_lock(raw_rwlock_t *lock)
{
unsigned long tmp1, tmp2;
@@ -184,7 +131,7 @@
: "memory");
}
-static void inline __read_unlock(rwlock_t *lock)
+static void inline __read_unlock(raw_rwlock_t *lock)
{
unsigned long tmp1, tmp2;
@@ -201,7 +148,7 @@
: "memory");
}
-static void inline __write_lock(rwlock_t *lock)
+static void inline __write_lock(raw_rwlock_t *lock)
{
unsigned long mask, tmp1, tmp2;
@@ -228,7 +175,7 @@
: "memory");
}
-static void inline __write_unlock(rwlock_t *lock)
+static void inline __write_unlock(raw_rwlock_t *lock)
{
__asm__ __volatile__(
" membar #LoadStore | #StoreStore\n"
@@ -238,7 +185,7 @@
: "memory");
}
-static int inline __write_trylock(rwlock_t *lock)
+static int inline __write_trylock(raw_rwlock_t *lock)
{
unsigned long mask, tmp1, tmp2, result;
@@ -263,78 +210,15 @@
return result;
}
-#define _raw_read_lock(p) __read_lock(p)
-#define _raw_read_unlock(p) __read_unlock(p)
-#define _raw_write_lock(p) __write_lock(p)
-#define _raw_write_unlock(p) __write_unlock(p)
-#define _raw_write_trylock(p) __write_trylock(p)
+#define __raw_read_lock(p) __read_lock(p)
+#define __raw_read_unlock(p) __read_unlock(p)
+#define __raw_write_lock(p) __write_lock(p)
+#define __raw_write_unlock(p) __write_unlock(p)
+#define __raw_write_trylock(p) __write_trylock(p)
-#else /* !(CONFIG_DEBUG_SPINLOCK) */
-
-typedef struct {
- volatile unsigned long lock;
- unsigned int writer_pc, writer_cpu;
- unsigned int reader_pc[NR_CPUS];
-#ifdef CONFIG_PREEMPT
- unsigned int break_lock;
-#endif
-} rwlock_t;
-#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, 0xff, { } }
-#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
-
-extern void _do_read_lock(rwlock_t *rw, char *str, unsigned long caller);
-extern void _do_read_unlock(rwlock_t *rw, char *str, unsigned long caller);
-extern void _do_write_lock(rwlock_t *rw, char *str, unsigned long caller);
-extern void _do_write_unlock(rwlock_t *rw, unsigned long caller);
-extern int _do_write_trylock(rwlock_t *rw, char *str, unsigned long caller);
-
-#define _raw_read_lock(lock) \
-do { unsigned long flags; \
- local_irq_save(flags); \
- _do_read_lock(lock, "read_lock", \
- (unsigned long) __builtin_return_address(0)); \
- local_irq_restore(flags); \
-} while(0)
-
-#define _raw_read_unlock(lock) \
-do { unsigned long flags; \
- local_irq_save(flags); \
- _do_read_unlock(lock, "read_unlock", \
- (unsigned long) __builtin_return_address(0)); \
- local_irq_restore(flags); \
-} while(0)
-
-#define _raw_write_lock(lock) \
-do { unsigned long flags; \
- local_irq_save(flags); \
- _do_write_lock(lock, "write_lock", \
- (unsigned long) __builtin_return_address(0)); \
- local_irq_restore(flags); \
-} while(0)
-
-#define _raw_write_unlock(lock) \
-do { unsigned long flags; \
- local_irq_save(flags); \
- _do_write_unlock(lock, \
- (unsigned long) __builtin_return_address(0)); \
- local_irq_restore(flags); \
-} while(0)
-
-#define _raw_write_trylock(lock) \
-({ unsigned long flags; \
- int val; \
- local_irq_save(flags); \
- val = _do_write_trylock(lock, "write_trylock", \
- (unsigned long) __builtin_return_address(0)); \
- local_irq_restore(flags); \
- val; \
-})
-
-#endif /* CONFIG_DEBUG_SPINLOCK */
-
-#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
-#define read_can_lock(rw) (!((rw)->lock & 0x80000000UL))
-#define write_can_lock(rw) (!(rw)->lock)
+#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
+#define __raw_read_can_lock(rw) (!((rw)->lock & 0x80000000UL))
+#define __raw_write_can_lock(rw) (!(rw)->lock)
#endif /* !(__ASSEMBLY__) */