From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=0vny=62=vger.kernel.org=linux-kernel-owner@kernel.org>
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=-0.8 required=3.0 tests=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 B674BCA90AF
	for <linux-kernel@archiver.kernel.org>; Tue, 12 May 2020 16:31:28 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by mail.kernel.org (Postfix) with ESMTP id 8F100206F5
	for <linux-kernel@archiver.kernel.org>; Tue, 12 May 2020 16:31:28 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727998AbgELQb1 (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Tue, 12 May 2020 12:31:27 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57218 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1726558AbgELQb1 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 12 May 2020 12:31:27 -0400
Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50A5FC061A0C
        for <linux-kernel@vger.kernel.org>; Tue, 12 May 2020 09:31:27 -0700 (PDT)
Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de)
        by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256)
        (Exim 4.80)
        (envelope-from <tglx@linutronix.de>)
        id 1jYXnz-0000EL-PC; Tue, 12 May 2020 18:30:56 +0200
Received: by nanos.tec.linutronix.de (Postfix, from userid 1000)
        id C90951004DE; Tue, 12 May 2020 18:30:54 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Alexandre Chartre <alexandre.chartre@oracle.com>,
        LKML <linux-kernel@vger.kernel.org>
Cc:     x86@kernel.org, "Paul E. McKenney" <paulmck@kernel.org>,
        Andy Lutomirski <luto@kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Petr Mladek <pmladek@suse.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Juergen Gross <jgross@suse.com>,
        Brian Gerst <brgerst@gmail.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Will Deacon <will@kernel.org>
Subject: Re: [patch V4 part 5 07/31] x86/entry: Provide idtentry_entry/exit_cond_rcu()
In-Reply-To: <72cb3e24-3f82-7e2a-7630-233749c780c4@oracle.com>
References: <20200505135341.730586321@linutronix.de> <20200505135828.808686575@linutronix.de> <72cb3e24-3f82-7e2a-7630-233749c780c4@oracle.com>
Date:   Tue, 12 May 2020 18:30:54 +0200
Message-ID: <878shx5d4x.fsf@nanos.tec.linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain
X-Linutronix-Spam-Score: -1.0
X-Linutronix-Spam-Level: -
X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required,  ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Alexandre Chartre <alexandre.chartre@oracle.com> writes:
> On 5/5/20 3:53 PM, Thomas Gleixner wrote:
>> The pagefault handler cannot use the regular idtentry_enter() because on
>> that invokes rcu_irq_enter() the pagefault was caused in the kernel.
>
> I am struggling to understand this part of the sentence: "because on
> that invokes rcu_irq_enter() the pagefault was caused in the kernel."
>
> Do you mean: "because that invokes rcu_irq_enter() if the pagefault was
> caused in the kernel." ?

Yeah. Wordsalad ...