Sometimes when debugging large multi-threaded applications it is helpful to
collate all of the latency numbers into one bulk record to get an idea of what
is going on. This patch does this by merging any entries that belong to the
same comm into one entry and then spits out those totals. I've also sligtly
changed the output so you can see how many threads were merged in the
processing. Thanks,
Signed-off-by: Josef Bacik <[email protected]>
---
tools/perf/builtin-sched.c | 77 +++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 72 insertions(+), 5 deletions(-)
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 5275bab..c74894f 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -95,6 +95,7 @@ struct work_atoms {
u64 total_lat;
u64 nb_atoms;
u64 total_runtime;
+ int num_merged;
};
typedef int (*sort_fn_t)(struct work_atoms *, struct work_atoms *);
@@ -168,9 +169,10 @@ struct perf_sched {
u64 all_runtime;
u64 all_count;
u64 cpu_last_switched[MAX_CPUS];
- struct rb_root atom_root, sorted_atom_root;
+ struct rb_root atom_root, sorted_atom_root, merged_atom_root;
struct list_head sort_list, cmp_pid;
bool force;
+ bool merge_by_comm;
};
static u64 get_nsecs(void)
@@ -1156,7 +1158,10 @@ static void output_lat_thread(struct perf_sched *sched, struct work_atoms *work_
sched->all_runtime += work_list->total_runtime;
sched->all_count += work_list->nb_atoms;
- ret = printf(" %s:%d ", thread__comm_str(work_list->thread), work_list->thread->tid);
+ if (sched->merge_by_comm && work_list->num_merged > 1)
+ ret = printf(" %s:(%d) ", thread__comm_str(work_list->thread), work_list->num_merged);
+ else
+ ret = printf(" %s:%d ", thread__comm_str(work_list->thread), work_list->thread->tid);
for (i = 0; i < 24 - ret; i++)
printf(" ");
@@ -1276,17 +1281,22 @@ static int sort_dimension__add(const char *tok, struct list_head *list)
static void perf_sched__sort_lat(struct perf_sched *sched)
{
struct rb_node *node;
-
+ struct rb_root *root = &sched->atom_root;
+again:
for (;;) {
struct work_atoms *data;
- node = rb_first(&sched->atom_root);
+ node = rb_first(root);
if (!node)
break;
- rb_erase(node, &sched->atom_root);
+ rb_erase(node, root);
data = rb_entry(node, struct work_atoms, node);
__thread_latency_insert(&sched->sorted_atom_root, data, &sched->sort_list);
}
+ if (root == &sched->atom_root) {
+ root = &sched->merged_atom_root;
+ goto again;
+ }
}
static int process_sched_wakeup_event(struct perf_tool *tool,
@@ -1542,6 +1552,59 @@ static void print_bad_events(struct perf_sched *sched)
}
}
+static void __merge_work_atoms(struct rb_root *root, struct work_atoms *data)
+{
+ struct rb_node **new = &(root->rb_node), *parent = NULL;
+ struct work_atoms *this;
+ const char *comm = thread__comm_str(data->thread), *this_comm;
+
+ while (*new) {
+ int cmp;
+
+ this = container_of(*new, struct work_atoms, node);
+ parent = *new;
+
+ this_comm = thread__comm_str(this->thread);
+ cmp = strcmp(comm, this_comm);
+ if (cmp > 0) {
+ new = &((*new)->rb_left);
+ } else if (cmp < 0) {
+ new = &((*new)->rb_right);
+ } else {
+ this->num_merged++;
+ this->total_runtime += data->total_runtime;
+ this->nb_atoms += data->nb_atoms;
+ this->total_lat += data->total_lat;
+ list_splice(&data->work_list, &this->work_list);
+ if (this->max_lat < data->max_lat) {
+ this->max_lat = data->max_lat;
+ this->max_lat_at = data->max_lat_at;
+ }
+ zfree(&data);
+ return;
+ }
+ }
+
+ data->num_merged++;
+ rb_link_node(&data->node, parent, new);
+ rb_insert_color(&data->node, root);
+}
+
+static void perf_sched__merge_lat(struct perf_sched *sched)
+{
+ struct work_atoms *data;
+ struct rb_node *node;
+
+ if (!sched->merge_by_comm)
+ return;
+
+ while ((node = rb_first(&sched->atom_root))) {
+ rb_erase(node, &sched->atom_root);
+ data = rb_entry(node, struct work_atoms, node);
+ __merge_work_atoms(&sched->merged_atom_root, data);
+ }
+}
+
static int perf_sched__lat(struct perf_sched *sched)
{
struct rb_node *next;
@@ -1551,6 +1614,7 @@ static int perf_sched__lat(struct perf_sched *sched)
if (perf_sched__read_events(sched))
return -1;
+ perf_sched__merge_lat(sched);
perf_sched__sort_lat(sched);
printf("\n -----------------------------------------------------------------------------------------------------------------\n");
@@ -1702,6 +1766,7 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
.profile_cpu = -1,
.next_shortname1 = 'A',
.next_shortname2 = '0',
+ .merge_by_comm = 0,
};
const struct option latency_options[] = {
OPT_STRING('s', "sort", &sched.sort_order, "key[,key2...]",
@@ -1712,6 +1777,8 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
"CPU to profile on"),
OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
"dump raw trace in ASCII"),
+ OPT_BOOLEAN('m', "merge-by-comm", &sched.merge_by_comm,
+ "merge like tasks together in the output"),
OPT_END()
};
const struct option replay_options[] = {
--
2.1.0
* Josef Bacik <[email protected]> wrote:
> Sometimes when debugging large multi-threaded applications it is helpful to
> collate all of the latency numbers into one bulk record to get an idea of what
> is going on. This patch does this by merging any entries that belong to the
> same comm into one entry and then spits out those totals. I've also sligtly
s/sligtly
slightly
> changed the output so you can see how many threads were merged in the
> processing. Thanks,
Useful feature!
> + OPT_BOOLEAN('m', "merge-by-comm", &sched.merge_by_comm,
> + "merge like tasks together in the output"),
Could you please make this the default behavior, and then add an
option to print more detailed latencies?
We generally try to output general overviews first, and then make it
easy to also output a more detailed view of information. That's how
perf report, perf top and perf stat (-d, -dd, -ddd) works in general.
Also, please post a before/after sample output in the changelog.
Thanks,
Ingo