Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932425Ab3DYNrR (ORCPT ); Thu, 25 Apr 2013 09:47:17 -0400 Received: from mail-la0-f54.google.com ([209.85.215.54]:51774 "EHLO mail-la0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932319Ab3DYNq6 (ORCPT ); Thu, 25 Apr 2013 09:46:58 -0400 MIME-Version: 1.0 In-Reply-To: <20130425134101.GA16609@gmail.com> References: <20130425134101.GA16609@gmail.com> Date: Thu, 25 Apr 2013 15:46:55 +0200 Message-ID: Subject: Re: Kconfig doesn't support select on choices (was Re: [GIT PULL] nohz: Adaptively stop the tick, finally) From: Frederic Weisbecker To: Ingo Molnar Cc: Michal Marek , LKML , Chris Metcalf , Christoph Lameter , Geoff Levand , Gilad Ben Yossef , Hakan Akkan , Kevin Hilman , Li Zhong , Oleg Nesterov , "Paul E. McKenney" , Paul Gortmaker , Peter Zijlstra , Steven Rostedt , Thomas Gleixner , Stephane Eranian , Jiri Olsa Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1916 Lines: 46 2013/4/25 Ingo Molnar : > > * Frederic Weisbecker wrote: > >> 2013/4/25 Ingo Molnar : >> > >> > * Frederic Weisbecker wrote: >> > >> >> > depends on VIRT_CPU_ACCOUNTING_GEN >> >> > >> >> > It should _really_ select both the RCU and the CPU time accounting model >> >> > automatically! >> >> >> >> Yeah I know. I have yet to fix that in Kconfig (it's a Kconfig limitation). >> > >> > Why cannot we simply select it and its dependencies, explicitly, for the >> > time being? Something like: >> > >> > depends on 64BIT >> > select VIRT_CPU_ACCOUNTING >> > select VIRT_CPU_ACCOUNTING_GEN >> > >> > 90% of the .config's have VIRT_CPU_ACCOUNTING_GEN turned off, because it's >> > a default-off feature - so dynticks-full is effectively hidden from the >> > large majority of testers... >> >> Whatever we do, it seems that select does not work with choices. >> >> Michal, we are running into an issue where a Kconfig option needs to >> select CONFIG_VIRT_CPU_ACCOUNTING_GEN but this latter option is part of >> a choice menu so it doesn't work. As a result we are forced to use a >> "depends on" and this hides the high level option we are interested in >> (here full dynticks) behind its low level dependency. How hard do you >> think it would be to fix this? I tried something that worked half-way >> but I quickly got lost in the Kconfig maze. > > While it's not an ideal solution, we could try to create three bools out > of the choice options, as a workaround? I thought about that yeah, at least for a temporary solution. Let's try it, I'll see what I can get. -- 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/