Revision 7f453c24b95a085fc7bd35d53b33abc4dc5a048b authored by Peter Zijlstra on 21 July 2009, 11:19:40 UTC, committed by Peter Zijlstra on 22 July 2009, 16:05:56 UTC
Anton noted that for inherited counters the counter-id as provided by PERF_SAMPLE_ID isn't mappable to the id found through PERF_RECORD_ID because each inherited counter gets its own id. His suggestion was to always return the parent counter id, since that is the primary counter id as exposed. However, these inherited counters have a unique identifier so that events like PERF_EVENT_PERIOD and PERF_EVENT_THROTTLE can be specific about which counter gets modified, which is important when trying to normalize the sample streams. This patch removes PERF_EVENT_PERIOD in favour of PERF_SAMPLE_PERIOD, which is more useful anyway, since changing periods became a lot more common than initially thought -- rendering PERF_EVENT_PERIOD the less useful solution (also, PERF_SAMPLE_PERIOD reports the more accurate value, since it reports the value used to trigger the overflow, whereas PERF_EVENT_PERIOD simply reports the requested period changed, which might only take effect on the next cycle). This still leaves us PERF_EVENT_THROTTLE to consider, but since that _should_ be a rare occurrence, and linking it to a primary id is the most useful bit to diagnose the problem, we introduce a PERF_SAMPLE_STREAM_ID, for those few cases where the full reconstruction is important. [Does change the ABI a little, but I see no other way out] Suggested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1248095846.15751.8781.camel@twins>
1 parent 573402d
spinlock.c
/*
* Copyright (2004) Linus Torvalds
*
* Author: Zwane Mwaikambo <zwane@fsmlabs.com>
*
* Copyright (2004, 2005) Ingo Molnar
*
* This file contains the spinlock/rwlock implementations for the
* SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)
*
* Note that some architectures have special knowledge about the
* stack frames of these functions in their profile_pc. If you
* change anything significant here that could change the stack
* frame contact the architecture maintainers.
*/
#include <linux/linkage.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include <linux/module.h>
int __lockfunc _spin_trylock(spinlock_t *lock)
{
preempt_disable();
if (_raw_spin_trylock(lock)) {
spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return 1;
}
preempt_enable();
return 0;
}
EXPORT_SYMBOL(_spin_trylock);
int __lockfunc _read_trylock(rwlock_t *lock)
{
preempt_disable();
if (_raw_read_trylock(lock)) {
rwlock_acquire_read(&lock->dep_map, 0, 1, _RET_IP_);
return 1;
}
preempt_enable();
return 0;
}
EXPORT_SYMBOL(_read_trylock);
int __lockfunc _write_trylock(rwlock_t *lock)
{
preempt_disable();
if (_raw_write_trylock(lock)) {
rwlock_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return 1;
}
preempt_enable();
return 0;
}
EXPORT_SYMBOL(_write_trylock);
/*
* If lockdep is enabled then we use the non-preemption spin-ops
* even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
* not re-enabled during lock-acquire (which the preempt-spin-ops do):
*/
#if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
void __lockfunc _read_lock(rwlock_t *lock)
{
preempt_disable();
rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
}
EXPORT_SYMBOL(_read_lock);
unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
/*
* On lockdep we dont want the hand-coded irq-enable of
* _raw_spin_lock_flags() code, because lockdep assumes
* that interrupts are not re-enabled during lock-acquire:
*/
#ifdef CONFIG_LOCKDEP
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
#else
_raw_spin_lock_flags(lock, &flags);
#endif
return flags;
}
EXPORT_SYMBOL(_spin_lock_irqsave);
void __lockfunc _spin_lock_irq(spinlock_t *lock)
{
local_irq_disable();
preempt_disable();
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_irq);
void __lockfunc _spin_lock_bh(spinlock_t *lock)
{
local_bh_disable();
preempt_disable();
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_bh);
unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED_FLAGS(lock, _raw_read_trylock, _raw_read_lock,
_raw_read_lock_flags, &flags);
return flags;
}
EXPORT_SYMBOL(_read_lock_irqsave);
void __lockfunc _read_lock_irq(rwlock_t *lock)
{
local_irq_disable();
preempt_disable();
rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
}
EXPORT_SYMBOL(_read_lock_irq);
void __lockfunc _read_lock_bh(rwlock_t *lock)
{
local_bh_disable();
preempt_disable();
rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
}
EXPORT_SYMBOL(_read_lock_bh);
unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED_FLAGS(lock, _raw_write_trylock, _raw_write_lock,
_raw_write_lock_flags, &flags);
return flags;
}
EXPORT_SYMBOL(_write_lock_irqsave);
void __lockfunc _write_lock_irq(rwlock_t *lock)
{
local_irq_disable();
preempt_disable();
rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
}
EXPORT_SYMBOL(_write_lock_irq);
void __lockfunc _write_lock_bh(rwlock_t *lock)
{
local_bh_disable();
preempt_disable();
rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
}
EXPORT_SYMBOL(_write_lock_bh);
void __lockfunc _spin_lock(spinlock_t *lock)
{
preempt_disable();
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock);
void __lockfunc _write_lock(rwlock_t *lock)
{
preempt_disable();
rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
}
EXPORT_SYMBOL(_write_lock);
#else /* CONFIG_PREEMPT: */
/*
* This could be a long-held lock. We both prepare to spin for a long
* time (making _this_ CPU preemptable if possible), and we also signal
* towards that other CPU that it should break the lock ASAP.
*
* (We do this in a function because inlining it would be excessive.)
*/
#define BUILD_LOCK_OPS(op, locktype) \
void __lockfunc _##op##_lock(locktype##_t *lock) \
{ \
for (;;) { \
preempt_disable(); \
if (likely(_raw_##op##_trylock(lock))) \
break; \
preempt_enable(); \
\
if (!(lock)->break_lock) \
(lock)->break_lock = 1; \
while (!op##_can_lock(lock) && (lock)->break_lock) \
_raw_##op##_relax(&lock->raw_lock); \
} \
(lock)->break_lock = 0; \
} \
\
EXPORT_SYMBOL(_##op##_lock); \
\
unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \
{ \
unsigned long flags; \
\
for (;;) { \
preempt_disable(); \
local_irq_save(flags); \
if (likely(_raw_##op##_trylock(lock))) \
break; \
local_irq_restore(flags); \
preempt_enable(); \
\
if (!(lock)->break_lock) \
(lock)->break_lock = 1; \
while (!op##_can_lock(lock) && (lock)->break_lock) \
_raw_##op##_relax(&lock->raw_lock); \
} \
(lock)->break_lock = 0; \
return flags; \
} \
\
EXPORT_SYMBOL(_##op##_lock_irqsave); \
\
void __lockfunc _##op##_lock_irq(locktype##_t *lock) \
{ \
_##op##_lock_irqsave(lock); \
} \
\
EXPORT_SYMBOL(_##op##_lock_irq); \
\
void __lockfunc _##op##_lock_bh(locktype##_t *lock) \
{ \
unsigned long flags; \
\
/* */ \
/* Careful: we must exclude softirqs too, hence the */ \
/* irq-disabling. We use the generic preemption-aware */ \
/* function: */ \
/**/ \
flags = _##op##_lock_irqsave(lock); \
local_bh_disable(); \
local_irq_restore(flags); \
} \
\
EXPORT_SYMBOL(_##op##_lock_bh)
/*
* Build preemption-friendly versions of the following
* lock-spinning functions:
*
* _[spin|read|write]_lock()
* _[spin|read|write]_lock_irq()
* _[spin|read|write]_lock_irqsave()
* _[spin|read|write]_lock_bh()
*/
BUILD_LOCK_OPS(spin, spinlock);
BUILD_LOCK_OPS(read, rwlock);
BUILD_LOCK_OPS(write, rwlock);
#endif /* CONFIG_PREEMPT */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
{
preempt_disable();
spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_nested);
unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock,
_raw_spin_lock_flags, &flags);
return flags;
}
EXPORT_SYMBOL(_spin_lock_irqsave_nested);
void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
struct lockdep_map *nest_lock)
{
preempt_disable();
spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_nest_lock);
#endif
void __lockfunc _spin_unlock(spinlock_t *lock)
{
spin_release(&lock->dep_map, 1, _RET_IP_);
_raw_spin_unlock(lock);
preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock);
void __lockfunc _write_unlock(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_write_unlock(lock);
preempt_enable();
}
EXPORT_SYMBOL(_write_unlock);
void __lockfunc _read_unlock(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_read_unlock(lock);
preempt_enable();
}
EXPORT_SYMBOL(_read_unlock);
void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
spin_release(&lock->dep_map, 1, _RET_IP_);
_raw_spin_unlock(lock);
local_irq_restore(flags);
preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock_irqrestore);
void __lockfunc _spin_unlock_irq(spinlock_t *lock)
{
spin_release(&lock->dep_map, 1, _RET_IP_);
_raw_spin_unlock(lock);
local_irq_enable();
preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock_irq);
void __lockfunc _spin_unlock_bh(spinlock_t *lock)
{
spin_release(&lock->dep_map, 1, _RET_IP_);
_raw_spin_unlock(lock);
preempt_enable_no_resched();
local_bh_enable_ip((unsigned long)__builtin_return_address(0));
}
EXPORT_SYMBOL(_spin_unlock_bh);
void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_read_unlock(lock);
local_irq_restore(flags);
preempt_enable();
}
EXPORT_SYMBOL(_read_unlock_irqrestore);
void __lockfunc _read_unlock_irq(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_read_unlock(lock);
local_irq_enable();
preempt_enable();
}
EXPORT_SYMBOL(_read_unlock_irq);
void __lockfunc _read_unlock_bh(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_read_unlock(lock);
preempt_enable_no_resched();
local_bh_enable_ip((unsigned long)__builtin_return_address(0));
}
EXPORT_SYMBOL(_read_unlock_bh);
void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_write_unlock(lock);
local_irq_restore(flags);
preempt_enable();
}
EXPORT_SYMBOL(_write_unlock_irqrestore);
void __lockfunc _write_unlock_irq(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_write_unlock(lock);
local_irq_enable();
preempt_enable();
}
EXPORT_SYMBOL(_write_unlock_irq);
void __lockfunc _write_unlock_bh(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_write_unlock(lock);
preempt_enable_no_resched();
local_bh_enable_ip((unsigned long)__builtin_return_address(0));
}
EXPORT_SYMBOL(_write_unlock_bh);
int __lockfunc _spin_trylock_bh(spinlock_t *lock)
{
local_bh_disable();
preempt_disable();
if (_raw_spin_trylock(lock)) {
spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return 1;
}
preempt_enable_no_resched();
local_bh_enable_ip((unsigned long)__builtin_return_address(0));
return 0;
}
EXPORT_SYMBOL(_spin_trylock_bh);
notrace 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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