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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 35F47C04EBF for ; Tue, 4 Dec 2018 22:34:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0613120850 for ; Tue, 4 Dec 2018 22:34:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0613120850 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=joshtriplett.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726592AbeLDWen (ORCPT ); Tue, 4 Dec 2018 17:34:43 -0500 Received: from mslow2.mail.gandi.net ([217.70.178.242]:42128 "EHLO mslow2.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725875AbeLDWen (ORCPT ); Tue, 4 Dec 2018 17:34:43 -0500 Received: from relay9-d.mail.gandi.net (unknown [217.70.183.199]) by mslow2.mail.gandi.net (Postfix) with ESMTP id CACDB3A2B88; Tue, 4 Dec 2018 23:24:21 +0100 (CET) X-Originating-IP: 134.134.139.82 Received: from localhost (unknown [134.134.139.82]) (Authenticated sender: josh@joshtriplett.org) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id DF8EEFF803; Tue, 4 Dec 2018 22:24:17 +0000 (UTC) Date: Tue, 4 Dec 2018 14:24:13 -0800 From: Josh Triplett To: tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org Cc: linux-tip-commits@vger.kernel.org Subject: Re: [tip:core/rcu] rcutorture: Make initrd/init execute in userspace Message-ID: <20181204222412.GA6874@localhost> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 04, 2018 at 02:09:42PM -0800, tip-bot for Paul E. McKenney wrote: > --- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh > +++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh > @@ -39,9 +39,22 @@ mkdir $T > > cat > $T/init << '__EOF___' > #!/bin/sh > +# Run in userspace a few milliseconds every second. This helps to > +# exercise the NO_HZ_FULL portions of RCU. > while : > do > - sleep 1000000 > + q= > + for i in \ > + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ > + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ > + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ > + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ > + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ > + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a Ow. If there's no better way to do this, please do at least comment how many 'a's this is. (And why 186, exactly?) Please also consider calibrating the delay loop as you do in the C code.