From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751740AbaHOKnz (ORCPT ); Fri, 15 Aug 2014 06:43:55 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:38980 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750954AbaHOKny (ORCPT ); Fri, 15 Aug 2014 06:43:54 -0400 Date: Fri, 15 Aug 2014 11:43:34 +0100 From: Will Deacon To: Rohit Vaswani Cc: Stephen Boyd , Russell King , Catalin Marinas , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH] arm64: smp: Update the topology masks before calling CPU_STARTING notifiers Message-ID: <20140815104333.GH27466@arm.com> References: <1407892269-28650-1-git-send-email-rvaswani@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1407892269-28650-1-git-send-email-rvaswani@codeaurora.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 13, 2014 at 02:11:09AM +0100, Rohit Vaswani wrote: > Currently, the CPU_STARTING notifiers would observe an incorrect sibling > mask since the notifier chain is called before the topology masks are updated > for the new cpu. > Update the topology masks before calling the notifier chain to fix this > problem. > > Signed-off-by: Rohit Vaswani > --- > arch/arm/kernel/smp.c | 4 ++-- > arch/arm64/kernel/smp.c | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c > index 7c4fada..0e2237c 100644 > --- a/arch/arm/kernel/smp.c > +++ b/arch/arm/kernel/smp.c > @@ -363,12 +363,12 @@ asmlinkage void secondary_start_kernel(void) > if (smp_ops.smp_secondary_init) > smp_ops.smp_secondary_init(cpu); > > + smp_store_cpu_info(cpu); > + > notify_cpu_starting(cpu); > > calibrate_delay(); > > - smp_store_cpu_info(cpu); > - Hmm, smp_store_cpu_info takes a copy of loops_per_jiffy. Are you sure it's safe to move the call before calibrate_delay? Will