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perf_counter: provide generic callchain bits

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Provide the generic callchain support bits. If hw_event->callchain is
set the arch specific perf_callchain() function is called upon to
provide a perf_callchain_entry structure filled with the current
callchain.

If it does so, it is added to the overflow output event.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171024.254266860@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2009-03-30 19:07:14 +02:00
committed by Ingo Molnar
parent 023c54c422
commit 394ee07623
2 changed files with 39 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
include/linux/perf_counter.h
View File

@@ -140,8 +140,9 @@ struct perf_counter_hw_event {
include_tid : 1, /* include the tid */ include_tid : 1, /* include the tid */
mmap : 1, /* include mmap data */ mmap : 1, /* include mmap data */
munmap : 1, /* include munmap data */ munmap : 1, /* include munmap data */
callchain : 1, /* add callchain data */
__reserved_1 : 52; __reserved_1 : 51;
__u32 extra_config_len; __u32 extra_config_len;
__u32 __reserved_4; __u32 __reserved_4;
@@ -219,6 +220,7 @@ enum perf_event_type {
PERF_EVENT_OVERFLOW = 1UL << 31, PERF_EVENT_OVERFLOW = 1UL << 31,
__PERF_EVENT_IP = 1UL << 30, __PERF_EVENT_IP = 1UL << 30,
__PERF_EVENT_TID = 1UL << 29, __PERF_EVENT_TID = 1UL << 29,
__PERF_EVENT_CALLCHAIN = 1UL << 28,
}; };
#ifdef __KERNEL__ #ifdef __KERNEL__
@@ -504,6 +506,15 @@ extern void perf_counter_mmap(unsigned long addr, unsigned long len,
extern void perf_counter_munmap(unsigned long addr, unsigned long len, extern void perf_counter_munmap(unsigned long addr, unsigned long len,
unsigned long pgoff, struct file *file); unsigned long pgoff, struct file *file);
#define MAX_STACK_DEPTH 255
struct perf_callchain_entry {
u64 nr;
u64 ip[MAX_STACK_DEPTH];
};
extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
#else #else
static inline void static inline void
perf_counter_task_sched_in(struct task_struct *task, int cpu) { } perf_counter_task_sched_in(struct task_struct *task, int cpu) { }

27
kernel/perf_counter.c
View File

@@ -1653,6 +1653,17 @@ void perf_counter_do_pending(void)
__perf_pending_run(); __perf_pending_run();
} }
/*
* Callchain support -- arch specific
*/
struct perf_callchain_entry *
__attribute__((weak))
perf_callchain(struct pt_regs *regs)
{
return NULL;
}
/* /*
* Output * Output
*/ */
@@ -1764,6 +1775,8 @@ static void perf_output_simple(struct perf_counter *counter,
struct { struct {
u32 pid, tid; u32 pid, tid;
} tid_entry; } tid_entry;
struct perf_callchain_entry *callchain = NULL;
int callchain_size = 0;
header.type = PERF_EVENT_OVERFLOW; header.type = PERF_EVENT_OVERFLOW;
header.size = sizeof(header); header.size = sizeof(header);
@@ -1781,6 +1794,17 @@ static void perf_output_simple(struct perf_counter *counter,
header.size += sizeof(tid_entry); header.size += sizeof(tid_entry);
} }
if (counter->hw_event.callchain) {
callchain = perf_callchain(regs);
if (callchain) {
callchain_size = (1 + callchain->nr) * sizeof(u64);
header.type |= __PERF_EVENT_CALLCHAIN;
header.size += callchain_size;
}
}
ret = perf_output_begin(&handle, counter, header.size, nmi); ret = perf_output_begin(&handle, counter, header.size, nmi);
if (ret) if (ret)
return; return;
@@ -1791,6 +1815,9 @@ static void perf_output_simple(struct perf_counter *counter,
if (counter->hw_event.include_tid) if (counter->hw_event.include_tid)
perf_output_put(&handle, tid_entry); perf_output_put(&handle, tid_entry);
if (callchain)
perf_output_copy(&handle, callchain, callchain_size);
perf_output_end(&handle); perf_output_end(&handle);
} }