From patchwork Mon Feb 18 02:50:23 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shawn Guo X-Patchwork-Id: 2155021 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id C5F433FE37 for ; Mon, 18 Feb 2013 02:53:51 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1U7GoT-0005ZX-OT; Mon, 18 Feb 2013 02:50:41 +0000 Received: from co9ehsobe005.messaging.microsoft.com ([207.46.163.28] helo=co9outboundpool.messaging.microsoft.com) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U7GoP-0005ZC-DC for linux-arm-kernel@lists.infradead.org; Mon, 18 Feb 2013 02:50:37 +0000 Received: from mail160-co9-R.bigfish.com (10.236.132.235) by CO9EHSOBE024.bigfish.com (10.236.130.87) with Microsoft SMTP Server id 14.1.225.23; Mon, 18 Feb 2013 02:50:28 +0000 Received: from mail160-co9 (localhost [127.0.0.1]) by mail160-co9-R.bigfish.com (Postfix) with ESMTP id 8A2452E024C; Mon, 18 Feb 2013 02:50:27 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: -2 X-BigFish: VS-2(zz98dI1432Izz1f42h1ee6h1de0h1202h1e76h1d1ah1d2ahzzz2dh87h2a8h668h839h944hd25hf0ah1220h1288h12a5h12a9h12bdh137ah13b6h1441h1504h1537h153bh162dh1631h1758h18e1h1946h19b5h1155h) X-FB-DOMAIN-IP-MATCH: fail Received: from mail160-co9 (localhost.localdomain [127.0.0.1]) by mail160-co9 (MessageSwitch) id 13611558224626_30525; Mon, 18 Feb 2013 02:50:22 +0000 (UTC) Received: from CO9EHSMHS003.bigfish.com (unknown [10.236.132.253]) by mail160-co9.bigfish.com (Postfix) with ESMTP id F2E91C0058; Mon, 18 Feb 2013 02:50:21 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by CO9EHSMHS003.bigfish.com (10.236.130.13) with Microsoft SMTP Server (TLS) id 14.1.225.23; Mon, 18 Feb 2013 02:50:21 +0000 Received: from az84smr01.freescale.net (10.64.34.197) by 039-SN1MMR1-005.039d.mgd.msft.net (10.84.1.17) with Microsoft SMTP Server (TLS) id 14.2.328.11; Mon, 18 Feb 2013 02:50:20 +0000 Received: from S2101-09.ap.freescale.net ([10.192.185.100]) by az84smr01.freescale.net (8.14.3/8.14.0) with ESMTP id r1I2oAS3028303; Sun, 17 Feb 2013 19:50:15 -0700 Date: Mon, 18 Feb 2013 10:50:23 +0800 From: Shawn Guo To: Russell King - ARM Linux Subject: Re: i.MX6 Solo: maxcpus=1 vs. nosmp: Warning from smp_twd.c? Message-ID: <20130218025021.GI6782@S2101-09.ap.freescale.net> References: <511CF063.3010200@de.bosch.com> <20130214143752.GH17833@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20130214143752.GH17833@n2100.arm.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginatorOrg: sigmatel.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130217_215037_590448_25E22C9A X-CRM114-Status: GOOD ( 16.66 ) X-Spam-Score: -4.2 (----) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-4.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [207.46.163.28 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Dirk Behme , dirk.behme@gmail.com, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org On Thu, Feb 14, 2013 at 02:37:52PM +0000, Russell King - ARM Linux wrote: > On Thu, Feb 14, 2013 at 03:10:43PM +0100, Dirk Behme wrote: > > working on a i.MX6 Solo SoC (one Cortex A9 core) we are usually booting > > with maxcpus=1 a kernel built with CONFIG_NR_CPUS=4. This is done to be > > able to boot the same kernel on the Solo and Quad version of that SoC. > > And what happens if you compile a kernel without SMP support and boot > it on this SoC? Thanks Dirk for bringing this up on the list. We have hit this fat warning on FSL internal 3.5.7 kernel tree when booting SMP kernel with nosmp on kernel cmdline. As what Dirk confirmed, we do not see the warning with kernel built with !SMP. Russell, The following is an immediate and less invasive change to lower the warning level. If you agree, I will post a patch and then put it into patch system. Shawn diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c index c092115..f796b83 100644 --- a/arch/arm/kernel/smp_twd.c +++ b/arch/arm/kernel/smp_twd.c @@ -392,6 +392,6 @@ void __init twd_local_timer_of_register(void) err = twd_local_timer_common_register(np); out: - WARN(err, "twd_local_timer_of_register failed (%d)\n", err); + pr_warn("twd_local_timer_of_register failed (%d)\n", err); } #endif