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Subject[RFC PATCH v1 03/37] perf evlist: replace evsel__cpu_iter* functions with evsel__find_cpu
Date
Commit a8cbe40fe9f4ba49 ("perf evsel: Add iterator to iterate over events
ordered by CPU") introduced an iterator for evsel.core.cpus inside evsel
which is used to iterate over evlist one CPU at a time.

However, this solution is hacky since it involves a mutable state in the
evsel which is supposed to be unmodified during iteration.
Sice checking that a CPU is within the evsel can be done quickly in
O(logn) time, this patch replaces the aforementioned iterator with a
simple check.

Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
---
tools/perf/builtin-stat.c | 24 +++++++++--------
tools/perf/util/evlist.c | 54 +++++++++++----------------------------
tools/perf/util/evlist.h | 5 +---
tools/perf/util/evsel.h | 1 -
4 files changed, 30 insertions(+), 54 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 84de61795e67bbb9..62dcc001c8f0a78b 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -407,7 +407,7 @@ static int read_affinity_counters(struct timespec *rs)
{
struct evsel *counter;
struct affinity affinity;
- int i, ncpus, cpu;
+ int i, ncpus, cpu, cpu_idx;

if (all_counters_use_bpf)
return 0;
@@ -424,13 +424,14 @@ static int read_affinity_counters(struct timespec *rs)
affinity__set(&affinity, cpu);

evlist__for_each_entry(evsel_list, counter) {
- if (evsel__cpu_iter_skip(counter, cpu))
+ cpu_idx = evsel__find_cpu(counter, cpu);
+ if (cpu_idx < 0)
continue;
if (evsel__is_bpf(counter))
continue;
if (!counter->err) {
counter->err = read_counter_cpu(counter, rs,
- counter->cpu_iter - 1);
+ cpu_idx);
}
}
}
@@ -789,7 +790,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
const bool forks = (argc > 0);
bool is_pipe = STAT_RECORD ? perf_stat.data.is_pipe : false;
struct affinity affinity;
- int i, cpu, err;
+ int i, cpu, cpu_idx, err;
bool second_pass = false;

if (forks) {
@@ -823,7 +824,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
affinity__set(&affinity, cpu);

evlist__for_each_entry(evsel_list, counter) {
- if (evsel__cpu_iter_skip(counter, cpu))
+ cpu_idx = evsel__find_cpu(counter, cpu);
+ if (cpu_idx < 0)
continue;
if (counter->reset_group || counter->errored)
continue;
@@ -831,7 +833,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
continue;
try_again:
if (create_perf_stat_counter(counter, &stat_config, &target,
- counter->cpu_iter - 1) < 0) {
+ cpu_idx) < 0) {

/*
* Weak group failed. We cannot just undo this here
@@ -877,22 +879,24 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
evlist__for_each_entry(evsel_list, counter) {
if (!counter->reset_group && !counter->errored)
continue;
- if (evsel__cpu_iter_skip_no_inc(counter, cpu))
+ cpu_idx = evsel__find_cpu(counter, cpu);
+ if (cpu_idx < 0)
continue;
- perf_evsel__close_cpu(&counter->core, counter->cpu_iter);
+ perf_evsel__close_cpu(&counter->core, cpu_idx);
}
/* Now reopen weak */
evlist__for_each_entry(evsel_list, counter) {
if (!counter->reset_group && !counter->errored)
continue;
- if (evsel__cpu_iter_skip(counter, cpu))
+ cpu_idx = evsel__find_cpu(counter, cpu);
+ if (cpu_idx < 0)
continue;
if (!counter->reset_group)
continue;
try_again_reset:
pr_debug2("reopening weak %s\n", evsel__name(counter));
if (create_perf_stat_counter(counter, &stat_config, &target,
- counter->cpu_iter - 1) < 0) {
+ cpu_idx) < 0) {

switch (stat_handle_error(counter)) {
case COUNTER_FATAL:
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 47581a237c7a7848..3d55d9a53b9f4875 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -341,36 +341,9 @@ static int evlist__nr_threads(struct evlist *evlist, struct evsel *evsel)
return perf_thread_map__nr(evlist->core.threads);
}

-void evlist__cpu_iter_start(struct evlist *evlist)
+int evsel__find_cpu(struct evsel *ev, int cpu)
{
- struct evsel *pos;
-
- /*
- * Reset the per evsel cpu_iter. This is needed because
- * each evsel's cpumap may have a different index space,
- * and some operations need the index to modify
- * the FD xyarray (e.g. open, close)
- */
- evlist__for_each_entry(evlist, pos)
- pos->cpu_iter = 0;
-}
-
-bool evsel__cpu_iter_skip_no_inc(struct evsel *ev, int cpu)
-{
- if (ev->cpu_iter >= ev->core.cpus->nr)
- return true;
- if (cpu >= 0 && ev->core.cpus->map[ev->cpu_iter] != cpu)
- return true;
- return false;
-}
-
-bool evsel__cpu_iter_skip(struct evsel *ev, int cpu)
-{
- if (!evsel__cpu_iter_skip_no_inc(ev, cpu)) {
- ev->cpu_iter++;
- return false;
- }
- return true;
+ return perf_cpu_map__idx(ev->core.cpus, cpu);
}

static int evsel__strcmp(struct evsel *pos, char *evsel_name)
@@ -400,7 +373,7 @@ static void __evlist__disable(struct evlist *evlist, char *evsel_name)
{
struct evsel *pos;
struct affinity affinity;
- int cpu, i, imm = 0;
+ int cpu, i, imm = 0, cpu_idx;
bool has_imm = false;

if (affinity__setup(&affinity) < 0)
@@ -414,7 +387,8 @@ static void __evlist__disable(struct evlist *evlist, char *evsel_name)
evlist__for_each_entry(evlist, pos) {
if (evsel__strcmp(pos, evsel_name))
continue;
- if (evsel__cpu_iter_skip(pos, cpu))
+ cpu_idx = evsel__find_cpu(pos, cpu);
+ if (cpu_idx < 0)
continue;
if (pos->disabled || !evsel__is_group_leader(pos) || !pos->core.fd)
continue;
@@ -422,7 +396,7 @@ static void __evlist__disable(struct evlist *evlist, char *evsel_name)
has_imm = true;
if (pos->immediate != imm)
continue;
- evsel__disable_cpu(pos, pos->cpu_iter - 1);
+ evsel__disable_cpu(pos, cpu_idx);
}
}
if (!has_imm)
@@ -462,7 +436,7 @@ static void __evlist__enable(struct evlist *evlist, char *evsel_name)
{
struct evsel *pos;
struct affinity affinity;
- int cpu, i;
+ int cpu, i, cpu_idx;

if (affinity__setup(&affinity) < 0)
return;
@@ -473,11 +447,12 @@ static void __evlist__enable(struct evlist *evlist, char *evsel_name)
evlist__for_each_entry(evlist, pos) {
if (evsel__strcmp(pos, evsel_name))
continue;
- if (evsel__cpu_iter_skip(pos, cpu))
+ cpu_idx = evsel__find_cpu(pos, cpu);
+ if (cpu_idx < 0)
continue;
if (!evsel__is_group_leader(pos) || !pos->core.fd)
continue;
- evsel__enable_cpu(pos, pos->cpu_iter - 1);
+ evsel__enable_cpu(pos, cpu_idx);
}
}
affinity__cleanup(&affinity);
@@ -1264,7 +1239,7 @@ void evlist__close(struct evlist *evlist)
{
struct evsel *evsel;
struct affinity affinity;
- int cpu, i;
+ int cpu, i, cpu_idx;

/*
* With perf record core.cpus is usually NULL.
@@ -1282,9 +1257,10 @@ void evlist__close(struct evlist *evlist)
affinity__set(&affinity, cpu);

evlist__for_each_entry_reverse(evlist, evsel) {
- if (evsel__cpu_iter_skip(evsel, cpu))
- continue;
- perf_evsel__close_cpu(&evsel->core, evsel->cpu_iter - 1);
+ cpu_idx = evsel__find_cpu(evsel, cpu);
+ if (cpu_idx < 0)
+ continue;
+ perf_evsel__close_cpu(&evsel->core, cpu_idx);
}
}
affinity__cleanup(&affinity);
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 5c22383489ae4905..fde893170c7ba6d2 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -310,15 +310,12 @@ void evlist__to_front(struct evlist *evlist, struct evsel *move_evsel);
__evlist__for_each_entry_safe(&(evlist)->core.entries, tmp, evsel)

#define evlist__for_each_cpu(evlist, index, cpu) \
- evlist__cpu_iter_start(evlist); \
perf_cpu_map__for_each_cpu (cpu, index, (evlist)->core.all_cpus)

struct evsel *evlist__get_tracking_event(struct evlist *evlist);
void evlist__set_tracking_event(struct evlist *evlist, struct evsel *tracking_evsel);

-void evlist__cpu_iter_start(struct evlist *evlist);
-bool evsel__cpu_iter_skip(struct evsel *ev, int cpu);
-bool evsel__cpu_iter_skip_no_inc(struct evsel *ev, int cpu);
+int evsel__find_cpu(struct evsel *ev, int cpu);

struct evsel *evlist__find_evsel_by_str(struct evlist *evlist, const char *str);

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 80383096d51c5f00..eabccce406886320 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -119,7 +119,6 @@ struct evsel {
bool errored;
struct hashmap *per_pkg_mask;
int err;
- int cpu_iter;
struct {
evsel__sb_cb_t *cb;
void *data;
--
2.31.1
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