From nobody Wed Dec 17 03:00:57 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0E81C83003 for ; Thu, 24 Aug 2023 02:19:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239398AbjHXCTT (ORCPT ); Wed, 23 Aug 2023 22:19:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239332AbjHXCSf (ORCPT ); Wed, 23 Aug 2023 22:18:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FE0510C4 for ; Wed, 23 Aug 2023 19:18:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7FFA364AB2 for ; Thu, 24 Aug 2023 02:18:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F000DC433C9; Thu, 24 Aug 2023 02:18:32 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1qYzvx-001hWH-00; Wed, 23 Aug 2023 22:18:53 -0400 Message-ID: <20230824021852.814428025@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 23 Aug 2023 22:18:24 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , Beau Belgrave , Eric Vaughn Subject: [for-next][PATCH 12/14] tracing/user_events: Optimize safe list traversals References: <20230824021812.938245293@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Eric Vaughn Several of the list traversals in the user_events facility use safe list traversals where they could be using the unsafe versions instead. Replace these safe traversals with their unsafe counterparts in the interest of optimization. Link: https://lore.kernel.org/linux-trace-kernel/20230810194337.695983-1-er= vaughn@linux.microsoft.com Suggested-by: Beau Belgrave Signed-off-by: Eric Vaughn Acked-by: Beau Belgrave Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_user.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_u= ser.c index 33cb6af31f39..6f046650e527 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -1328,14 +1328,14 @@ static int user_field_set_string(struct ftrace_even= t_field *field, =20 static int user_event_set_print_fmt(struct user_event *user, char *buf, in= t len) { - struct ftrace_event_field *field, *next; + struct ftrace_event_field *field; struct list_head *head =3D &user->fields; int pos =3D 0, depth =3D 0; const char *str_func; =20 pos +=3D snprintf(buf + pos, LEN_OR_ZERO, "\""); =20 - list_for_each_entry_safe_reverse(field, next, head, link) { + list_for_each_entry_reverse(field, head, link) { if (depth !=3D 0) pos +=3D snprintf(buf + pos, LEN_OR_ZERO, " "); =20 @@ -1347,7 +1347,7 @@ static int user_event_set_print_fmt(struct user_event= *user, char *buf, int len) =20 pos +=3D snprintf(buf + pos, LEN_OR_ZERO, "\""); =20 - list_for_each_entry_safe_reverse(field, next, head, link) { + list_for_each_entry_reverse(field, head, link) { if (user_field_is_dyn_string(field->type, &str_func)) pos +=3D snprintf(buf + pos, LEN_OR_ZERO, ", %s(%s)", str_func, field->name); @@ -1732,7 +1732,7 @@ static int user_event_create(const char *raw_command) static int user_event_show(struct seq_file *m, struct dyn_event *ev) { struct user_event *user =3D container_of(ev, struct user_event, devent); - struct ftrace_event_field *field, *next; + struct ftrace_event_field *field; struct list_head *head; int depth =3D 0; =20 @@ -1740,7 +1740,7 @@ static int user_event_show(struct seq_file *m, struct= dyn_event *ev) =20 head =3D trace_get_fields(&user->call); =20 - list_for_each_entry_safe_reverse(field, next, head, link) { + list_for_each_entry_reverse(field, head, link) { if (depth =3D=3D 0) seq_puts(m, " "); else @@ -1816,13 +1816,14 @@ static bool user_field_match(struct ftrace_event_fi= eld *field, int argc, static bool user_fields_match(struct user_event *user, int argc, const char **argv) { - struct ftrace_event_field *field, *next; + struct ftrace_event_field *field; struct list_head *head =3D &user->fields; int i =3D 0; =20 - list_for_each_entry_safe_reverse(field, next, head, link) + list_for_each_entry_reverse(field, head, link) { if (!user_field_match(field, argc, argv, &i)) return false; + } =20 if (i !=3D argc) return false; --=20 2.40.1