From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753735AbcADWT1 (ORCPT ); Mon, 4 Jan 2016 17:19:27 -0500 Received: from mail-pf0-f177.google.com ([209.85.192.177]:34918 "EHLO mail-pf0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753657AbcADWTZ (ORCPT ); Mon, 4 Jan 2016 17:19:25 -0500 Subject: Re: [PATCH] ppc64: select HAVE_CONTEXT_TRACKING by default To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au References: <1449701034-5444-1-git-send-email-yang.shi@linaro.org> Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linaro-kernel@lists.linaro.org From: "Shi, Yang" Message-ID: <568AEFEA.4080400@linaro.org> Date: Mon, 4 Jan 2016 14:19:22 -0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <1449701034-5444-1-git-send-email-yang.shi@linaro.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi folks, Any comment on this is appreciated. Thanks, Yang On 12/9/2015 2:43 PM, Yang Shi wrote: > The functionality of context tracking has been implemented by PPC64 and > HAVE_CONTEXT_TRACKING was selected by pseries by default. > Actually, it is applicale to all PPC64 platforms, so select it in PPC64 > generic Kconfig. > > NO_HZ_FULL depends on it, with this change NO_HZ_FULL could be enabled > for all PPC64 machines. > > Signed-off-by: Yang Shi > --- > Following the instruction in Documentation/timers/NO_HZ.txt, I tested full nohz > on my FSL T2080 target, the below trace log shows it works well. > > user_loop-574 [001] d..1 137.044892: tick_stop: success=yes msg= > user_loop-574 [001] d.h1 138.044880: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=137796002092 > user_loop-574 [001] d.h1 139.044880: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=138796002129 > user_loop-574 [001] d.h1 140.044880: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=139796002219 > user_loop-574 [001] d.h1 141.044880: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=140796002229 > user_loop-574 [001] d.h1 142.044879: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=141796002159 > user_loop-574 [001] d.h1 143.044879: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=142796002142 > user_loop-574 [001] d.h1 144.044878: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=143796002046 > user_loop-574 [001] d.h1 145.044878: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=144796002189 > user_loop-574 [001] d.h1 146.044878: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=145796002199 > user_loop-574 [001] d.h1 147.044880: hrtimer_expire_entry: hrtimer=c00000007fd22d10 function=.tick_sched_timer now=146796003836 > > It shows the timer tick just comes in every second. > > It should be low risk to have problem on other PPC64 targets, although they are > not tested. > > arch/powerpc/platforms/Kconfig.cputype | 1 + > arch/powerpc/platforms/pseries/Kconfig | 1 - > 2 files changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype > index 142dff5..7b25dd1 100644 > --- a/arch/powerpc/platforms/Kconfig.cputype > +++ b/arch/powerpc/platforms/Kconfig.cputype > @@ -3,6 +3,7 @@ config PPC64 > default n > select HAVE_VIRT_CPU_ACCOUNTING > select ZLIB_DEFLATE > + select HAVE_CONTEXT_TRACKING > help > This option selects whether a 32-bit or a 64-bit kernel > will be built. > diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig > index bec90fb..6853148 100644 > --- a/arch/powerpc/platforms/pseries/Kconfig > +++ b/arch/powerpc/platforms/pseries/Kconfig > @@ -17,7 +17,6 @@ config PPC_PSERIES > select PPC_UDBG_16550 > select PPC_NATIVE > select PPC_DOORBELL > - select HAVE_CONTEXT_TRACKING > select HOTPLUG_CPU if SMP > select ARCH_RANDOM > select PPC_DOORBELL >