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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 46959C4167B for ; Mon, 7 Dec 2020 19:48:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 084F6239A1 for ; Mon, 7 Dec 2020 19:48:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727037AbgLGTr5 (ORCPT ); Mon, 7 Dec 2020 14:47:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:60646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726004AbgLGTr4 (ORCPT ); Mon, 7 Dec 2020 14:47:56 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 8ED15238A1; Mon, 7 Dec 2020 19:47:15 +0000 (UTC) Date: Mon, 7 Dec 2020 14:47:13 -0500 From: Steven Rostedt To: Lucas Stach Cc: Ingo Molnar , linux-kernel@vger.kernel.org, kernel@pengutronix.de Subject: Re: tracer_init_tracefs really slow Message-ID: <20201207144713.1b19afe2@gandalf.local.home> In-Reply-To: <31a0d6b7cf7326e7e2f55ab2b668defb0c10b140.camel@pengutronix.de> References: <68d7b3327052757d0cd6359a6c9015a85b437232.camel@pengutronix.de> <20201203211854.7e5caa49@oasis.local.home> <31a0d6b7cf7326e7e2f55ab2b668defb0c10b140.camel@pengutronix.de> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 07 Dec 2020 17:24:58 +0100 Lucas Stach wrote: > I would be happy to test a patch on our whimpy machines, though. :) Let me know if this helps: -- Steve diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 06134189e9a7..48aa5b6a7d15 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9062,7 +9062,10 @@ int tracing_init_dentry(void) extern struct trace_eval_map *__start_ftrace_eval_maps[]; extern struct trace_eval_map *__stop_ftrace_eval_maps[]; -static void __init trace_eval_init(void) +static struct workqueue_struct *eval_map_wq __initdata; +struct work_struct eval_map_work __initdata; + +static void __init eval_map_work_func(struct work_struct *work) { int len; @@ -9070,6 +9073,34 @@ static void __init trace_eval_init(void) trace_insert_eval_map(NULL, __start_ftrace_eval_maps, len); } +static int __init trace_eval_init(void) +{ + INIT_WORK(&eval_map_work, eval_map_work_func); + + eval_map_wq = alloc_workqueue("eval_map_wq", WQ_UNBOUND, 0); + if (!eval_map_wq) { + pr_err("Unable to allocate eval_map_wq\n"); + /* Do work here */ + eval_map_work_func(&eval_map_work); + return -ENOMEM; + } + + queue_work(eval_map_wq, &eval_map_work); + return 0; +} + +static int __init trace_eval_sync(void) +{ + /* Make sure the eval map updates are finished */ + if (eval_map_wq) + destroy_workqueue(eval_map_wq); + return 0; +} + +subsys_initcall(trace_eval_init); +late_initcall_sync(trace_eval_sync); + + #ifdef CONFIG_MODULES static void trace_module_add_evals(struct module *mod) { @@ -9171,8 +9202,6 @@ static __init int tracer_init_tracefs(void) trace_create_file("saved_tgids", 0444, NULL, NULL, &tracing_saved_tgids_fops); - trace_eval_init(); - trace_create_eval_file(NULL); #ifdef CONFIG_MODULES