From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936967AbeE2RSk (ORCPT ); Tue, 29 May 2018 13:18:40 -0400 Received: from mail-vk0-f68.google.com ([209.85.213.68]:39827 "EHLO mail-vk0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936622AbeE2RSh (ORCPT ); Tue, 29 May 2018 13:18:37 -0400 X-Google-Smtp-Source: ADUXVKIK4O+x5Zk0vP5P67th0HkVxRTyy02j2gm852Tfsl68JiRJrioMMSXJ873+DbAe9v7A+m3cP0qKAmTrlUE5jnE= MIME-Version: 1.0 In-Reply-To: References: <20180511235807.30834-1-jeremy.linton@arm.com> <20180517170523.h7tuvbzdfluuidcz@armageddon.cambridge.arm.com> <09fb3fe7-d703-43f1-74f7-f8cb5ff1f67a@arm.com> <551905a6-eaa8-97df-06ec-1ceedfbc164f@arm.com> <20180529150823.GD17159@arm.com> From: Geert Uytterhoeven Date: Tue, 29 May 2018 19:18:35 +0200 X-Google-Sender-Auth: QwHp4dUt7aVZEJd-rOh-WfuwIb8 Message-ID: Subject: Re: [PATCH v9 00/12] Support PPTT for ARM64 To: Robin Murphy Cc: Will Deacon , Mark Rutland , austinwc@codeaurora.org, tnowicki@caviumnetworks.com, Catalin Marinas , Palmer Dabbelt , linux-riscv@lists.infradead.org, wangxiongfeng2@huawei.com, vkilari@codeaurora.org, Lorenzo Pieralisi , jhugo@codeaurora.org, Morten.Rasmussen@arm.com, ACPI Devel Maling List , Len Brown , John Garry , Al Stone , Linux ARM , Ard Biesheuvel , Greg KH , "Rafael J. Wysocki" , Linux Kernel Mailing List , Jeremy Linton , Linux-Renesas , Hanjun Guo , Sudeep Holla , Dietmar Eggemann Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Robin, On Tue, May 29, 2018 at 7:08 PM, Robin Murphy wrote: > On 29/05/18 16:51, Geert Uytterhoeven wrote: >> On Tue, May 29, 2018 at 5:08 PM, Will Deacon wrote: >>> On Tue, May 29, 2018 at 02:18:40PM +0100, Sudeep Holla wrote: >>>> On 29/05/18 12:56, Geert Uytterhoeven wrote: >>>>> On Tue, May 29, 2018 at 1:14 PM, Sudeep Holla >>>>> wrote: >>>>>> On 29/05/18 11:48, Geert Uytterhoeven wrote: >>>>>>> System supend still works fine on systems with big cores only: >>>>>>> >>>>>>> R-Car H3 ES1.0 (4xCA57 (4xCA53 disabled in firmware)) >>>>>>> R-Car M3-N (2xCA57) >>>>>>> >>>>>>> Reverting this commit fixes the issue for me. >>>>>> >>>>>> I can't find anything that relates to system suspend in these patches >>>>>> unless they are messing with something during CPU hot plug-in back >>>>>> during resume. >>>>> >>>>> It's only the last patch that introduces the breakage. >>>> >>>> As specified in the commit log, it won't change any behavior for DT >>>> systems if it's non-NUMA or single node system. So I am still wondering >>>> what could trigger this regression. >>> >>> I wonder if we're somehow giving an uninitialised/invalid NUMA >>> configuration >>> to the scheduler, although I can't see how this would happen. >>> >>> Geert -- if you enable CONFIG_DEBUG_PER_CPU_MAPS=y and apply the diff >>> below >>> do you see anything shouting in dmesg? >> >> Thanks, but unfortunately it doesn't help. >> I added some debug code to print cpumask, but so far I don't see anything >> suspicious. > > Do you have CONFIG_NUMA enabled? On a hunch I've managed to reproduce what > looks like the same thing on a Juno board with NUMA=n; going in with > external debug it seems to be stuck in the loop in > init_sched_groups_capacity(), with an approximate stack trace of: CONFIG_NUMA is not set. I'm basically using renesas_defconfig from https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas.git/log/?h=topic/renesas-defconfig Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds