Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933706AbbBBW1h (ORCPT ); Mon, 2 Feb 2015 17:27:37 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:35026 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933565AbbBBW1d (ORCPT ); Mon, 2 Feb 2015 17:27:33 -0500 Date: Mon, 2 Feb 2015 14:27:32 -0800 From: Andrew Morton To: Christoph Jaeger Cc: linux-kernel@vger.kernel.org, Yalin Wang , Will Deacon , Russell King Subject: Re: [PATCH linux-next] lib: Kconfig: use bool instead of boolean Message-Id: <20150202142732.9ea4d2f604ef79cbe180f5fe@linux-foundation.org> In-Reply-To: <1422889156-19830-1-git-send-email-cj@linux.com> References: <1422889156-19830-1-git-send-email-cj@linux.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1476 Lines: 43 On Mon, 2 Feb 2015 09:59:16 -0500 Christoph Jaeger wrote: > Keyword 'boolean' for type definition attributes is considered > deprecated and, therefore, should not be used anymore. > > See http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com > See http://lkml.kernel.org/r/1419108071-11607-1-git-send-email-cj@linux.com > > ... > > --- a/lib/Kconfig > +++ b/lib/Kconfig > @@ -14,7 +14,7 @@ config BITREVERSE > tristate > > config HAVE_ARCH_BITREVERSE > - boolean > + bool > default n > depends on BITREVERSE > help Your patch patches 556d2f055bf6d ("ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction") which appears in linux-next via the ARM tree. There are many uses of "boolean" in lib/Kconfig. Converting just one of them is inefficient and odd. 556d2f055bf6d is a bit of a surprise. It looks good to me from a non-ARM perspective - the __builtin_constant_p() optimisation is sensible, although bitrev on a constant probably isn't very common. I'm not sure about the ARM part though! __bitrev8() is pretty damn fast. Presumably an inlined rbit instruction is faster still, but not very much? The Kconfig help text in 556d2f055bf6d rather needs some caring for. -- 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/