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perf thread-stack: Add thread_stack__br_sample_late()

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Add a thread stack function to create a branch stack 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/20200429150751.12570-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter 2020-04-29 18:07:48 +03:00 committed by Arnaldo Carvalho de Melo
parent 6cd2cbfc68
commit 3749e0bbde
2 changed files with 107 additions and 0 deletions
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104
tools/perf/util/thread-stack.c
View File

@ -645,6 +645,110 @@ void thread_stack__br_sample(struct thread *thread, int cpu,
}
}
/* Start of user space branch entries */
static bool us_start(struct branch_entry *be, u64 kernel_start, bool *start)
{
if (!*start)
*start = be->to && be->to < kernel_start;
return *start;
}
/*
* Start of branch entries after the ip fell in between 2 branches, or user
* space branch entries.
*/
static bool ks_start(struct branch_entry *be, u64 sample_ip, u64 kernel_start,
bool *start, struct branch_entry *nb)
{
if (!*start) {
*start = (nb && sample_ip >= be->to && sample_ip <= nb->from) ||
be->from < kernel_start ||
(be->to && be->to < kernel_start);
}
return *start;
}
/*
* Hardware sample records, created some time after the event occurred, need to
* have subsequent addresses removed from the branch stack.
*/
void thread_stack__br_sample_late(struct thread *thread, int cpu,
struct branch_stack *dst, unsigned int sz,
u64 ip, u64 kernel_start)
{
struct thread_stack *ts = thread__stack(thread, cpu);
struct branch_entry *d, *s, *spos, *ssz;
struct branch_stack *src;
unsigned int nr = 0;
bool start = false;
dst->nr = 0;
if (!ts)
return;
src = ts->br_stack_rb;
if (!src->nr)
return;
spos = &src->entries[ts->br_stack_pos];
ssz = &src->entries[ts->br_stack_sz];
d = &dst->entries[0];
s = spos;
if (ip < kernel_start) {
/*
* User space sample: start copying branch entries when the
* branch is in user space.
*/
for (s = spos; s < ssz && nr < sz; s++) {
if (us_start(s, kernel_start, &start)) {
*d++ = *s;
nr += 1;
}
}
if (src->nr >= ts->br_stack_sz) {
for (s = &src->entries[0]; s < spos && nr < sz; s++) {
if (us_start(s, kernel_start, &start)) {
*d++ = *s;
nr += 1;
}
}
}
} else {
struct branch_entry *nb = NULL;
/*
* Kernel space sample: start copying branch entries when the ip
* falls in between 2 branches (or the branch is in user space
* because then the start must have been missed).
*/
for (s = spos; s < ssz && nr < sz; s++) {
if (ks_start(s, ip, kernel_start, &start, nb)) {
*d++ = *s;
nr += 1;
}
nb = s;
}
if (src->nr >= ts->br_stack_sz) {
for (s = &src->entries[0]; s < spos && nr < sz; s++) {
if (ks_start(s, ip, kernel_start, &start, nb)) {
*d++ = *s;
nr += 1;
}
nb = s;
}
}
}
dst->nr = nr;
}
struct call_return_processor *
call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data),
void *data)

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

@ -91,6 +91,9 @@ void thread_stack__sample_late(struct thread *thread, int cpu,
u64 kernel_start);
void thread_stack__br_sample(struct thread *thread, int cpu,
struct branch_stack *dst, unsigned int sz);
void thread_stack__br_sample_late(struct thread *thread, int cpu,
struct branch_stack *dst, unsigned int sz,
u64 sample_ip, u64 kernel_start);
int thread_stack__flush(struct thread *thread);
void thread_stack__free(struct thread *thread);
size_t thread_stack__depth(struct thread *thread, int cpu);