Commit f178ffdf authored by Ian Rogers's avatar Ian Rogers Committed by Namhyung Kim
Browse files

perf trace: Ignore thread hashing in summary 



Commit 91e467bc ("perf machine: Use hashtable for machine
threads") made the iteration of thread tids unordered. The perf trace
--summary output sorts and prints each hash bucket, rather than all
threads globally. Change this behavior by turn all threads into a
list, sort the list by number of trace events then by tids, finally
print the list. This also allows the rbtree in threads to be not
accessed outside of machine.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240301053646.1449657-3-irogers@google.com
parent 2f1e20fe

tools/perf/builtin-trace.c

+23 −18
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ 
#include <linux/err.h>

#include <linux/filter.h>

#include <linux/kernel.h>

#include <linux/list_sort.h>

#include <linux/random.h>

#include <linux/stringify.h>

#include <linux/time64.h>
@@ -4312,34 +4313,38 @@ static unsigned long thread__nr_events(struct thread_trace *ttrace) 
	return ttrace ? ttrace->nr_events : 0;

}



DEFINE_RESORT_RB(threads,

		(thread__nr_events(thread__priv(a->thread)) <

		 thread__nr_events(thread__priv(b->thread))),

	struct thread *thread;

)

static int trace_nr_events_cmp(void *priv __maybe_unused,

			       const struct list_head *la,

			       const struct list_head *lb)

{

	entry->thread = rb_entry(nd, struct thread_rb_node, rb_node)->thread;

	struct thread_list *a = list_entry(la, struct thread_list, list);

	struct thread_list *b = list_entry(lb, struct thread_list, list);

	unsigned long a_nr_events = thread__nr_events(thread__priv(a->thread));

	unsigned long b_nr_events = thread__nr_events(thread__priv(b->thread));



	if (a_nr_events != b_nr_events)

		return a_nr_events < b_nr_events ? -1 : 1;



	/* Identical number of threads, place smaller tids first. */

	return thread__tid(a->thread) < thread__tid(b->thread)

		? -1

		: (thread__tid(a->thread) > thread__tid(b->thread) ? 1 : 0);

}



static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp)

{

	size_t printed = trace__fprintf_threads_header(fp);

	struct rb_node *nd;

	int i;



	for (i = 0; i < THREADS__TABLE_SIZE; i++) {

		DECLARE_RESORT_RB_MACHINE_THREADS(threads, trace->host, i);

	LIST_HEAD(threads);



		if (threads == NULL) {

			fprintf(fp, "%s", "Error sorting output by nr_events!\n");

			return 0;

		}

	if (machine__thread_list(trace->host, &threads) == 0) {

		struct thread_list *pos;



		resort_rb__for_each_entry(nd, threads)

			printed += trace__fprintf_thread(fp, threads_entry->thread, trace);

		list_sort(NULL, &threads, trace_nr_events_cmp);



		resort_rb__delete(threads);

		list_for_each_entry(pos, &threads, list)

			printed += trace__fprintf_thread(fp, pos->thread, trace);

	}

	thread_list__delete(&threads);

	return printed;

}

tools/perf/util/rb_resort.h

+0 −5
Original line number Diff line number Diff line
@@ -143,9 +143,4 @@ struct __name##_sorted *__name = __name##_sorted__new 
	DECLARE_RESORT_RB(__name)(&__ilist->rblist.entries.rb_root,		\

				  __ilist->rblist.nr_entries)



/* For 'struct machine->threads' */

#define DECLARE_RESORT_RB_MACHINE_THREADS(__name, __machine, hash_bucket)    \

 DECLARE_RESORT_RB(__name)(&__machine->threads[hash_bucket].entries.rb_root, \

			   __machine->threads[hash_bucket].nr)



#endif /* _PERF_RESORT_RB_H_ */