Received: by 2002:a25:1506:0:0:0:0:0 with SMTP id 6csp4509224ybv; Tue, 25 Feb 2020 21:49:20 -0800 (PST) X-Google-Smtp-Source: APXvYqxwi5w6gpE1EvqW2YAq1oC57nubVp7tUEGr7uVbraQIraYxovjIE3nF7A7MIjML8SsJPffz X-Received: by 2002:aca:5588:: with SMTP id j130mr1763901oib.122.1582696160723; Tue, 25 Feb 2020 21:49:20 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1582696160; cv=none; d=google.com; s=arc-20160816; b=mjRtAvghORnZO+BsHIiWNKjFbl+LRV7x0sT91hPGxUHZ1W4Eae7bjnoQaw4p3jqBwS K9x9+JoUXXqjeZ/sKgYpehacZ1g/j/pq3qCTPoRik6vtDVOgt9RKKfAqWuLlt/so4Z7b m5PSImyPzY/bJb0V9JCJo50oPyO5o1a/E3pcU3JSTJi57J68r+bSc1ypRhLiExwqp0/b lThhkX4LGrl2n0wCyHDP7U9j1YSQIF9W+HDSt+6t4KK6C8mV8q3xnyyAJ7/nSkpaCVJw SqvIVz2XNdMn8CnPOeWsaoMXnARrUGBsd29thgyKnalA61x1pAEiig7xGVHP5PdVbRdv e1mQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject:dkim-signature; bh=ORYXmErF0o0qp9gsDeaBZDWrwJVjkZe5LQevdVaDMUA=; b=mG+05/+23bs8gr/aJ0wwn1yPfhGdqrU9iphS1JPK1ZBLGTpojAJ3Nqn3aArYutIcXA uVe5Tk8LRXSmfGCNbT3yq9jE+U6xzd/Y6nIRCINJAG0Aqva4aKhD80k1DGrvIvbK0f6X T89urvW2Lr0DuUXKegBlpTR0i/xQDCkUJvjsv5PVAZPRf4l8gIzk4ahGVXEB+ZaBETVZ pqvCy1k84GdVvIrkNh+1laQRbqpaIBV19TMqAaLLaZqXGQlOatqnOffV+xgPMEDJ5sZY YwOhO8omBy0E2ik1hxZnPEZn3aubZ4SvvEN6FO/zPCV/wOJuX8UFUrdA6xyW4Y45MNTD 5Ulg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=ExGlz+jz; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id t184si549959oie.165.2020.02.25.21.49.08; Tue, 25 Feb 2020 21:49:20 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=ExGlz+jz; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726946AbgBZFrx (ORCPT + 99 others); Wed, 26 Feb 2020 00:47:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:39510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725789AbgBZFrx (ORCPT ); Wed, 26 Feb 2020 00:47:53 -0500 Received: from [192.168.0.217] (c-67-180-165-146.hsd1.ca.comcast.net [67.180.165.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C1254206E2; Wed, 26 Feb 2020 05:47:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582696073; bh=P593FGjMiFSyqNhPqxCl6EBKFcqaO+XUWMo+/sOtY50=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=ExGlz+jzi6fzSq8Sb7OpeytLapzqH+r/7nxMr7PfXGOG5pp5VvATzQb0GfJHc5jug 1nOheQNzThP534NEZnbaX5JkV/Fhm6IIVDuIEcfuOhu8+y9Cnfkn5wbqI+6roXcru1 7Yh0/rA3+Fr49sbwXEt5UJvPppP1p+7CDeBgcqfU= Subject: Re: [patch 6/8] x86/entry: Move irq tracing to syscall_slow_exit_work To: Thomas Gleixner , LKML Cc: x86@kernel.org, Steven Rostedt , Brian Gerst , Juergen Gross , Paolo Bonzini , Arnd Bergmann References: <20200225220801.571835584@linutronix.de> <20200225221305.813084267@linutronix.de> From: Andy Lutomirski Message-ID: Date: Tue, 25 Feb 2020 21:47:52 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200225221305.813084267@linutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/25/20 2:08 PM, Thomas Gleixner wrote: > which removes the ASM IRQ tracepoints. It's still after we re-enter rcuidle. Is tracing actually okay? I always had the impression that tracing was okay in rcuidle mode because the tracing code was smart enough to do the right thing, but your patch 3/8 changelog says: Anything before enter_from_user_mode() is not safe to be traced or probed. --Andy