Re: [PATCH][5/8] Arch agnostic completely out of line locks / ppc64
From: Anton Blanchard
Date: Thu Sep 09 2004 - 22:31:23 EST
> All in all, about four lines of code changes (+ some movement to make it
> all saner)
How does this look?
- create in_lock_functions() to match in_sched_functions(). Export it
for use in oprofile.
- use char __lock_text_start[] instead of long __lock_text_start when
declaring linker symbols. Rusty fixed a number of these a while ago
based on advice from rth.
- Move __preempt_*_lock into kernel/spinlock.c and make it inline. This
means locks are only one deep.
- Make in_sched_functions() check in_lock_functions()
I apologise if I have broken any architectures.
Anton
Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
diff -puN arch/arm/kernel/time.c~spinlockfix arch/arm/kernel/time.c
--- compat_affinity/arch/arm/kernel/time.c~spinlockfix 2004-09-10 13:13:50.266767502 +1000
+++ compat_affinity-anton/arch/arm/kernel/time.c 2004-09-10 13:13:50.347761276 +1000
@@ -57,8 +57,7 @@ unsigned long profile_pc(struct pt_regs
{
unsigned long fp, pc = instruction_pointer(regs);
- if (pc >= (unsigned long)&__lock_text_start &&
- pc <= (unsigned long)&__lock_text_end) {
+ if (in_lock_functions(pc)) {
fp = thread_saved_fp(current);
pc = pc_pointer(((unsigned long *)fp)[-1]);
}
diff -puN arch/i386/kernel/time.c~spinlockfix arch/i386/kernel/time.c
--- compat_affinity/arch/i386/kernel/time.c~spinlockfix 2004-09-10 13:13:50.272767040 +1000
+++ compat_affinity-anton/arch/i386/kernel/time.c 2004-09-10 13:13:50.349761122 +1000
@@ -205,8 +205,7 @@ unsigned long profile_pc(struct pt_regs
{
unsigned long pc = instruction_pointer(regs);
- if (pc >= (unsigned long)&__lock_text_start &&
- pc <= (unsigned long)&__lock_text_end)
+ if (in_lock_functions(pc))
return *(unsigned long *)(regs->ebp + 4);
return pc;
diff -puN arch/ppc/kernel/time.c~spinlockfix arch/ppc/kernel/time.c
--- compat_affinity/arch/ppc/kernel/time.c~spinlockfix 2004-09-10 13:13:50.278766579 +1000
+++ compat_affinity-anton/arch/ppc/kernel/time.c 2004-09-10 13:13:50.350761045 +1000
@@ -113,8 +113,7 @@ unsigned long profile_pc(struct pt_regs
{
unsigned long pc = instruction_pointer(regs);
- if (pc >= (unsigned long)&__lock_text_start &&
- pc <= (unsigned long)&__lock_text_end)
+ if (in_lock_functions(pc))
return regs->link;
return pc;
diff -puN arch/ppc64/kernel/rtasd.c~spinlockfix arch/ppc64/kernel/rtasd.c
diff -puN arch/ppc64/kernel/time.c~spinlockfix arch/ppc64/kernel/time.c
--- compat_affinity/arch/ppc64/kernel/time.c~spinlockfix 2004-09-10 13:13:50.290765657 +1000
+++ compat_affinity-anton/arch/ppc64/kernel/time.c 2004-09-10 13:13:50.353760815 +1000
@@ -163,8 +163,7 @@ unsigned long profile_pc(struct pt_regs
{
unsigned long pc = instruction_pointer(regs);
- if (pc >= (unsigned long)&__lock_text_start &&
- pc <= (unsigned long)&__lock_text_end)
+ if (in_lock_functions(pc))
return regs->link;
return pc;
diff -puN arch/sparc/kernel/time.c~spinlockfix arch/sparc/kernel/time.c
--- compat_affinity/arch/sparc/kernel/time.c~spinlockfix 2004-09-10 13:13:50.296765196 +1000
+++ compat_affinity-anton/arch/sparc/kernel/time.c 2004-09-10 13:13:50.355760661 +1000
@@ -81,20 +81,22 @@ struct intersil *intersil_clock;
unsigned long profile_pc(struct pt_regs *regs)
{
- extern int __copy_user_begin, __copy_user_end;
- extern int __atomic_begin, __atomic_end;
- extern int __bzero_begin, __bzero_end;
- extern int __bitops_begin, __bitops_end;
+ extern char __copy_user_begin[], __copy_user_end[];
+ extern char __atomic_begin[], __atomic_end[];
+ extern char __bzero_begin[], __bzero_end[];
+ extern char __bitops_begin[], __bitops_end[];
+
unsigned long pc = regs->pc;
- if ((pc >= (unsigned long) &__copy_user_begin &&
- pc < (unsigned long) &__copy_user_end) ||
- (pc >= (unsigned long) &__atomic_begin &&
- pc < (unsigned long) &__atomic_end) ||
- (pc >= (unsigned long) &__bzero_begin &&
- pc < (unsigned long) &__bzero_end) ||
- (pc >= (unsigned long) &__bitops_begin &&
- pc < (unsigned long) &__bitops_end))
+ if (in_lock_functions(pc) ||
+ (pc >= (unsigned long) __copy_user_begin &&
+ pc < (unsigned long) __copy_user_end) ||
+ (pc >= (unsigned long) __atomic_begin &&
+ pc < (unsigned long) __atomic_end) ||
+ (pc >= (unsigned long) __bzero_begin &&
+ pc < (unsigned long) __bzero_end) ||
+ (pc >= (unsigned long) __bitops_begin &&
+ pc < (unsigned long) __bitops_end))
pc = regs->u_regs[UREG_RETPC];
return pc;
}
diff -puN arch/sparc64/kernel/time.c~spinlockfix arch/sparc64/kernel/time.c
--- compat_affinity/arch/sparc64/kernel/time.c~spinlockfix 2004-09-10 13:13:50.302764735 +1000
+++ compat_affinity-anton/arch/sparc64/kernel/time.c 2004-09-10 13:13:50.358760430 +1000
@@ -73,8 +73,7 @@ unsigned long profile_pc(struct pt_regs
{
unsigned long pc = instruction_pointer(regs);
- if (pc >= (unsigned long)&__lock_text_start &&
- pc <= (unsigned long)&__lock_text_end)
+ if (in_lock_functions(pc))
return regs->u_regs[UREG_RETPC];
return pc;
}
diff -puN arch/x86_64/kernel/time.c~spinlockfix arch/x86_64/kernel/time.c
--- compat_affinity/arch/x86_64/kernel/time.c~spinlockfix 2004-09-10 13:13:50.308764273 +1000
+++ compat_affinity-anton/arch/x86_64/kernel/time.c 2004-09-10 13:13:50.361760200 +1000
@@ -184,8 +184,7 @@ unsigned long profile_pc(struct pt_regs
{
unsigned long pc = instruction_pointer(regs);
- if (pc >= (unsigned long)&__lock_text_start &&
- pc <= (unsigned long)&__lock_text_end)
+ if (in_lock_functions(pc))
return *(unsigned long *)regs->rbp;
return pc;
}
diff -puN include/linux/spinlock.h~spinlockfix include/linux/spinlock.h
--- compat_affinity/include/linux/spinlock.h~spinlockfix 2004-09-10 13:13:50.314763812 +1000
+++ compat_affinity-anton/include/linux/spinlock.h 2004-09-10 13:13:50.363760046 +1000
@@ -68,11 +68,11 @@ void __lockfunc _write_unlock_irqrestore
void __lockfunc _write_unlock_irq(rwlock_t *lock);
void __lockfunc _write_unlock_bh(rwlock_t *lock);
int __lockfunc _spin_trylock_bh(spinlock_t *lock);
-
-extern unsigned long __lock_text_start;
-extern unsigned long __lock_text_end;
+int in_lock_functions(unsigned long addr);
#else
+#define in_lock_functions(ADDR) 0
+
#if !defined(CONFIG_PREEMPT) && !defined(CONFIG_DEBUG_SPINLOCK)
# define atomic_dec_and_lock(atomic,lock) atomic_dec_and_test(atomic)
# define ATOMIC_DEC_AND_LOCK
diff -puN kernel/sched.c~spinlockfix kernel/sched.c
--- compat_affinity/kernel/sched.c~spinlockfix 2004-09-10 13:13:50.321763274 +1000
+++ compat_affinity-anton/kernel/sched.c 2004-09-10 13:13:50.373759277 +1000
@@ -4672,8 +4672,9 @@ int in_sched_functions(unsigned long add
{
/* Linker adds these: start and end of __sched functions */
extern char __sched_text_start[], __sched_text_end[];
- return addr >= (unsigned long)__sched_text_start
- && addr < (unsigned long)__sched_text_end;
+ return in_lock_functions(addr) ||
+ (addr >= (unsigned long)__sched_text_start
+ && addr < (unsigned long)__sched_text_end);
}
void __init sched_init(void)
@@ -4765,49 +4766,3 @@ void __might_sleep(char *file, int line)
}
EXPORT_SYMBOL(__might_sleep);
#endif
-
-
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
-/*
- * This could be a long-held lock. If another CPU holds it for a long time,
- * and that CPU is not asked to reschedule then *this* CPU will spin on the
- * lock for a long time, even if *this* CPU is asked to reschedule.
- *
- * So what we do here, in the slow (contended) path is to spin on the lock by
- * hand while permitting preemption.
- *
- * Called inside preempt_disable().
- */
-void __sched __preempt_spin_lock(spinlock_t *lock)
-{
- if (preempt_count() > 1) {
- _raw_spin_lock(lock);
- return;
- }
- do {
- preempt_enable();
- while (spin_is_locked(lock))
- cpu_relax();
- preempt_disable();
- } while (!_raw_spin_trylock(lock));
-}
-
-EXPORT_SYMBOL(__preempt_spin_lock);
-
-void __sched __preempt_write_lock(rwlock_t *lock)
-{
- if (preempt_count() > 1) {
- _raw_write_lock(lock);
- return;
- }
-
- do {
- preempt_enable();
- while (rwlock_is_locked(lock))
- cpu_relax();
- preempt_disable();
- } while (!_raw_write_trylock(lock));
-}
-
-EXPORT_SYMBOL(__preempt_write_lock);
-#endif /* defined(CONFIG_SMP) && defined(CONFIG_PREEMPT) */
diff -puN kernel/spinlock.c~spinlockfix kernel/spinlock.c
--- compat_affinity/kernel/spinlock.c~spinlockfix 2004-09-10 13:13:50.326762890 +1000
+++ compat_affinity-anton/kernel/spinlock.c 2004-09-10 13:19:40.103522704 +1000
@@ -33,7 +33,32 @@ int __lockfunc _write_trylock(rwlock_t *
}
EXPORT_SYMBOL(_write_trylock);
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
+#ifdef CONFIG_PREEMPT
+/*
+ * This could be a long-held lock. If another CPU holds it for a long time,
+ * and that CPU is not asked to reschedule then *this* CPU will spin on the
+ * lock for a long time, even if *this* CPU is asked to reschedule.
+ *
+ * So what we do here, in the slow (contended) path is to spin on the lock by
+ * hand while permitting preemption.
+ *
+ * Called inside preempt_disable().
+ */
+static inline void __preempt_spin_lock(spinlock_t *lock)
+{
+ if (preempt_count() > 1) {
+ _raw_spin_lock(lock);
+ return;
+ }
+
+ do {
+ preempt_enable();
+ while (spin_is_locked(lock))
+ cpu_relax();
+ preempt_disable();
+ } while (!_raw_spin_trylock(lock));
+}
+
void __lockfunc _spin_lock(spinlock_t *lock)
{
preempt_disable();
@@ -41,6 +66,21 @@ void __lockfunc _spin_lock(spinlock_t *l
__preempt_spin_lock(lock);
}
+static inline void __preempt_write_lock(rwlock_t *lock)
+{
+ if (preempt_count() > 1) {
+ _raw_write_lock(lock);
+ return;
+ }
+
+ do {
+ preempt_enable();
+ while (rwlock_is_locked(lock))
+ cpu_relax();
+ preempt_disable();
+ } while (!_raw_write_trylock(lock));
+}
+
void __lockfunc _write_lock(rwlock_t *lock)
{
preempt_disable();
@@ -256,3 +296,13 @@ int __lockfunc _spin_trylock_bh(spinlock
return 0;
}
EXPORT_SYMBOL(_spin_trylock_bh);
+
+int in_lock_functions(unsigned long addr)
+{
+ /* Linker adds these: start and end of __lockfunc functions */
+ extern char __lock_text_start[], __lock_text_end[];
+
+ return addr >= (unsigned long)__lock_text_start
+ && addr < (unsigned long)__lock_text_end;
+}
+EXPORT_SYMBOL(in_lock_functions);
_
-
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