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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 A9E20C433E5 for ; Thu, 16 Jul 2020 13:04:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8355A2074B for ; Thu, 16 Jul 2020 13:04:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="R+CHDMGs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728696AbgGPNEZ (ORCPT ); Thu, 16 Jul 2020 09:04:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728119AbgGPNEZ (ORCPT ); Thu, 16 Jul 2020 09:04:25 -0400 Received: from mail-ua1-x944.google.com (mail-ua1-x944.google.com [IPv6:2607:f8b0:4864:20::944]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20995C061755 for ; Thu, 16 Jul 2020 06:04:25 -0700 (PDT) Received: by mail-ua1-x944.google.com with SMTP id c7so1733266uap.0 for ; Thu, 16 Jul 2020 06:04:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Oi4DIrXnzNzQ5ZyA1cvK/p3EIijpd8ykpkJ+JZfklOk=; b=R+CHDMGszW+/cumSKs6oY3KunQsv+l0cu8CoJ1eyarc/5vG6hHy7BvFDHuSw3uSJLe vFr/QRA1gIYxbUt7zJUmTluI3Zw+rfW+y0gkmqrzo9lfC2/dQfW5DBd7dypbU2xgVJfi L0IFCVIdpzf+O7NeL/VE6kx3GhV1PeGDGj8zYVfQMO6mRvxNW7QaID3Kz7fN726ZtI+m mI6WAjAPO7gdyCuRp7Mu6C4853dNTnlO+/tvybQHeH1K1PaMoAEqn5LWdA9yqE108QDd glLQKUvcS27gr202xjE7NHKxHQcHUqBWgXcYYHb08/QFuwJL0yfPJ4yq1ChkF7IeSLDq GnfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Oi4DIrXnzNzQ5ZyA1cvK/p3EIijpd8ykpkJ+JZfklOk=; b=sOs2WXyJF3NNHIAa+RRxT77jUa21aCPbfNtQNwZgx+aXZ0jZQoF+F7qqvGsCNld8vH fp7FIq+RTtKOjYdJEfwBq7Tl9B5GbwehB0EJGv6pjM2Rj+Kcx1GHRS39c1EF6KqL93ft NnQPlHufW5bGasy2rZ8pWBGlHx2qUXZDRJDKwNvHxqQ3YRJ9YM+ADtVu0sbTQVCNKbv1 hkSPoU7IRkRwBql7JGkcESuo7/KeVn4zohK9PyTL+/4yNZCnXALNv+TULuaIJzEEh4Mw PqQgrJeK6AVlhdlLSDn6gv5ibze8MBPyq7DnkxWZqasHcmYIysB/103fsZ7v3xKK/Yyq wIlw== X-Gm-Message-State: AOAM533SuAMfrdrULCwrtWcjTZRAMVqnokNUuiMuSULNl+IT1uTDGcrA bTTm29hKzxks6wusYwaPfW6gn6JTlp/M7b3jGJgcxvyH X-Google-Smtp-Source: ABdhPJzob9llZOr5+NOSWzWehlMOV+u2CGpQfysu/ut5OYGAuqH5DBeK8r2PhzdiiSnX5GPB5uaq4HyMZK0s57Z6C0A= X-Received: by 2002:ab0:7811:: with SMTP id x17mr3127867uaq.140.1594904664208; Thu, 16 Jul 2020 06:04:24 -0700 (PDT) MIME-Version: 1.0 References: <20200713212054.2e675557@oasis.local.home> <20200715153632.3f9dc5d3@oasis.local.home> In-Reply-To: <20200715153632.3f9dc5d3@oasis.local.home> From: Itai Handler Date: Thu, 16 Jul 2020 16:04:12 +0300 Message-ID: Subject: Re: aarch64 boot time increases with rt To: Steven Rostedt Cc: linux-rt-users@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Hi Steven, On Wed, Jul 15, 2020 at 10:36 PM Steven Rostedt wrote: > To rule out that this may be an issue with the function_graph tracer, > can you also try it with: > > ftrace=function ftrace_filter=worqueue_prepare_cpu > > And see if the function tracer shows anything. > > /me just looked at the code. > > Yes, the function tracer is set up to trace really early, but the > function_graph tracer is initialized by core_initcall(), which is much > later. > > Perhaps try this patch (note, it's from latest mainline): > > And retry the function_graph tracer. With this patch, the function graph tracer doesn't work at boot time. Please see the log below: # mount -t debugfs debugfs /sys/kernel/debug/ # cd /sys/kernel/debug/tracing/trace # cat current_tracer nop Note that I tested it both on 5.4.47-rt28 and 5.6.19-rt11 (but not on latest mainline). Regarding the function tracer, you were correct: it can trace workqueue_prepare_cpu without any issue. Thank you, Itai Handler