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perf thread-stack: Add thread_stack__sample_late()

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Add a thread stack function to create a call chain for hardware events
where the sample records get created some time after the event occurred.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200401101613.6201-10-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter
2020-04-01 13:16:06 +03:00
committed by Arnaldo Carvalho de Melo
parent 1c5c25b3fd
commit 4fef41bfb1
2 changed files with 60 additions and 0 deletions
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57
tools/perf/util/thread-stack.c
View File

@@ -497,6 +497,63 @@ void thread_stack__sample(struct thread *thread, int cpu,
chain->nr = i; chain->nr = i;
} }
/*
* Hardware sample records, created some time after the event occurred, need to
* have subsequent addresses removed from the call chain.
*/
void thread_stack__sample_late(struct thread *thread, int cpu,
struct ip_callchain *chain, size_t sz,
u64 sample_ip, u64 kernel_start)
{
struct thread_stack *ts = thread__stack(thread, cpu);
u64 sample_context = callchain_context(sample_ip, kernel_start);
u64 last_context, context, ip;
size_t nr = 0, j;
if (sz < 2) {
chain->nr = 0;
return;
}
if (!ts)
goto out;
/*
* When tracing kernel space, kernel addresses occur at the top of the
* call chain after the event occurred but before tracing stopped.
* Skip them.
*/
for (j = 1; j <= ts->cnt; j++) {
ip = ts->stack[ts->cnt - j].ret_addr;
context = callchain_context(ip, kernel_start);
if (context == PERF_CONTEXT_USER ||
(context == sample_context && ip == sample_ip))
break;
}
last_context = sample_ip; /* Use sample_ip as an invalid context */
for (; nr < sz && j <= ts->cnt; nr++, j++) {
ip = ts->stack[ts->cnt - j].ret_addr;
context = callchain_context(ip, kernel_start);
if (context != last_context) {
if (nr >= sz - 1)
break;
chain->ips[nr++] = context;
last_context = context;
}
chain->ips[nr] = ip;
}
out:
if (nr) {
chain->nr = nr;
} else {
chain->ips[0] = sample_context;
chain->ips[1] = sample_ip;
chain->nr = 2;
}
}
struct call_return_processor * struct call_return_processor *
call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data), call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data),
void *data) void *data)

3
tools/perf/util/thread-stack.h
View File

@@ -85,6 +85,9 @@ int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip,
void thread_stack__set_trace_nr(struct thread *thread, int cpu, u64 trace_nr); void thread_stack__set_trace_nr(struct thread *thread, int cpu, u64 trace_nr);
void thread_stack__sample(struct thread *thread, int cpu, struct ip_callchain *chain, void thread_stack__sample(struct thread *thread, int cpu, struct ip_callchain *chain,
size_t sz, u64 ip, u64 kernel_start); size_t sz, u64 ip, u64 kernel_start);
void thread_stack__sample_late(struct thread *thread, int cpu,
struct ip_callchain *chain, size_t sz, u64 ip,
u64 kernel_start);
int thread_stack__flush(struct thread *thread); int thread_stack__flush(struct thread *thread);
void thread_stack__free(struct thread *thread); void thread_stack__free(struct thread *thread);
size_t thread_stack__depth(struct thread *thread, int cpu); size_t thread_stack__depth(struct thread *thread, int cpu);