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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31501C433EF for ; Wed, 27 Apr 2022 19:38:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234000AbiD0Tle (ORCPT ); Wed, 27 Apr 2022 15:41:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233575AbiD0Tj5 (ORCPT ); Wed, 27 Apr 2022 15:39:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA0DE1016 for ; Wed, 27 Apr 2022 12:36:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9C54461B71 for ; Wed, 27 Apr 2022 19:36:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79933C385A9; Wed, 27 Apr 2022 19:36:44 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1njnSt-002Izw-Gd; Wed, 27 Apr 2022 15:36:43 -0400 Message-ID: <20220427193643.341238948@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 27 Apr 2022 15:36:44 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Mark-PK Tsai Subject: [for-next][PATCH 21/21] tracing: make tracer_init_tracefs initcall asynchronous References: <20220427193623.529296556@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mark-PK Tsai Move trace_eval_init() to subsys_initcall to make it start earlier. And to avoid tracer_init_tracefs being blocked by trace_event_sem which trace_eval_init() hold [1], queue tracer_init_tracefs() to eval_map_wq to let the two works being executed sequentially. It can speed up the initialization of kernel as result of making tracer_init_tracefs asynchronous. On my arm64 platform, it reduce ~20ms of 125ms which total time do_initcalls spend. Link: https://lkml.kernel.org/r/20220426122407.17042-3-mark-pk.tsai@mediatek.com [1]: https://lore.kernel.org/r/68d7b3327052757d0cd6359a6c9015a85b437232.camel@pengutronix.de Signed-off-by: Mark-PK Tsai Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7275173c55d0..400d3e9fe9ff 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9615,6 +9615,7 @@ extern struct trace_eval_map *__stop_ftrace_eval_maps[]; static struct workqueue_struct *eval_map_wq __initdata; static struct work_struct eval_map_work __initdata; +static struct work_struct tracerfs_init_work __initdata; static void __init eval_map_work_func(struct work_struct *work) { @@ -9640,6 +9641,8 @@ static int __init trace_eval_init(void) return 0; } +subsys_initcall(trace_eval_init); + static int __init trace_eval_sync(void) { /* Make sure the eval map updates are finished */ @@ -9722,15 +9725,8 @@ static struct notifier_block trace_module_nb = { }; #endif /* CONFIG_MODULES */ -static __init int tracer_init_tracefs(void) +static __init void tracer_init_tracefs_work_func(struct work_struct *work) { - int ret; - - trace_access_lock_init(); - - ret = tracing_init_dentry(); - if (ret) - return 0; event_trace_init(); @@ -9752,8 +9748,6 @@ static __init int tracer_init_tracefs(void) trace_create_file("saved_tgids", TRACE_MODE_READ, NULL, NULL, &tracing_saved_tgids_fops); - trace_eval_init(); - trace_create_eval_file(NULL); #ifdef CONFIG_MODULES @@ -9768,6 +9762,24 @@ static __init int tracer_init_tracefs(void) create_trace_instances(NULL); update_tracer_options(&global_trace); +} + +static __init int tracer_init_tracefs(void) +{ + int ret; + + trace_access_lock_init(); + + ret = tracing_init_dentry(); + if (ret) + return 0; + + if (eval_map_wq) { + INIT_WORK(&tracerfs_init_work, tracer_init_tracefs_work_func); + queue_work(eval_map_wq, &tracerfs_init_work); + } else { + tracer_init_tracefs_work_func(NULL); + } return 0; } -- 2.35.1