Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760680Ab3GSQ3K (ORCPT ); Fri, 19 Jul 2013 12:29:10 -0400 Received: from mail-wg0-f41.google.com ([74.125.82.41]:47902 "EHLO mail-wg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754828Ab3GSQ3I (ORCPT ); Fri, 19 Jul 2013 12:29:08 -0400 Date: Fri, 19 Jul 2013 18:29:04 +0200 From: Frederic Weisbecker To: Kevin Hilman Cc: Russell King , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Paul McKenney , linaro-kernel@lists.linaro.org Subject: Re: [PATCH 1/3] nohz: Kconfig: remove redundant 64-bit dependency Message-ID: <20130719162903.GC21752@somewhere> References: <1372876601-23881-1-git-send-email-khilman@linaro.org> <1372876601-23881-2-git-send-email-khilman@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1372876601-23881-2-git-send-email-khilman@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1712 Lines: 44 On Wed, Jul 03, 2013 at 11:36:39AM -0700, Kevin Hilman wrote: > The current 64-bit dependency is on VIRT_CPU_ACCOUNTING_GEN, which already > has its own dependency on 64-bit. Remove it from NO_HZ_FULL. It's not exactly redundant. It's a necessary dependency inheritance. When we select NO_HZ_FULL, TICK_CPU_ACCOUNTING and VIRT_CPU_ACCOUNTING_NATIVE disappear such that only VIRT_CPU_ACCOUNTING_GEN can be selected. But if we don't have CONFIG_64bits, then VIRT_CPU_ACCOUNTING_GEN is not possible either. So we end up with nothing for the accounting (or whatever random reaction from Kconfig against that situation) and that's a bug. So we need to inherit the 64 bits dependency on NO_HZ_FULL to prevent that. We can remove this dependency from NO_HZ_FULL, but only once we remove it from VIRT_CPU_ACCOUNTING_GEN, not the other way around otherwise this breaks bisection. > > Cc: Frederic Weisbecker > Signed-off-by: Kevin Hilman > --- > kernel/time/Kconfig | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig > index 70f27e8..b78760f 100644 > --- a/kernel/time/Kconfig > +++ b/kernel/time/Kconfig > @@ -99,8 +99,6 @@ config NO_HZ_FULL > depends on SMP > # RCU_USER_QS dependency > depends on HAVE_CONTEXT_TRACKING > - # VIRT_CPU_ACCOUNTING_GEN dependency > - depends on 64BIT > select NO_HZ_COMMON > select RCU_USER_QS > select RCU_NOCB_CPU > -- > 1.8.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/