From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EACF4C43387 for ; Fri, 21 Dec 2018 17:57:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB9A7218E0 for ; Fri, 21 Dec 2018 17:57:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391234AbeLUR5T (ORCPT ); Fri, 21 Dec 2018 12:57:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:56082 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391164AbeLUR5A (ORCPT ); Fri, 21 Dec 2018 12:57:00 -0500 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E99CB21920; Fri, 21 Dec 2018 17:56:59 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.91) (envelope-from ) id 1gaP2h-0002Re-09; Fri, 21 Dec 2018 12:56:59 -0500 Message-Id: <20181221175658.872681406@goodmis.org> User-Agent: quilt/0.65 Date: Fri, 21 Dec 2018 12:56:39 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Namhyung Kim , Masami Hiramatsu , Rasmus Villemoes Subject: [for-next][PATCH 21/24] tracing: Simplify printfing in seq_print_sym References: <20181221175618.968519903@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rasmus Villemoes trace_seq_printf(..., "%s", ...) can be done with trace_seq_puts() instead, avoiding printf overhead. In the second instance, the string we're copying was just created from an snprintf() to a stack buffer, so we might as well do that printf directly. This naturally leads to moving the declaration of the str buffer inside the CONFIG_KALLSYMS guard, which in turn will make gcc inline the function for !CONFIG_KALLSYMS (it only has a single caller, but the huge stack frame seems to make gcc not inline it for CONFIG_KALLSYMS). Link: http://lkml.kernel.org/r/20181029223542.26175-4-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_output.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index f06fb899b746..54373d93e251 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -341,8 +341,8 @@ static inline const char *kretprobed(const char *name) static void seq_print_sym(struct trace_seq *s, unsigned long address, bool offset) { - char str[KSYM_SYMBOL_LEN]; #ifdef CONFIG_KALLSYMS + char str[KSYM_SYMBOL_LEN]; const char *name; if (offset) @@ -352,12 +352,11 @@ seq_print_sym(struct trace_seq *s, unsigned long address, bool offset) name = kretprobed(str); if (name && strlen(name)) { - trace_seq_printf(s, "%s", name); + trace_seq_puts(s, name); return; } #endif - snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address); - trace_seq_printf(s, "%s", str); + trace_seq_printf(s, "0x%08lx", address); } #ifndef CONFIG_64BIT -- 2.19.2