Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755734AbZAGNTV (ORCPT ); Wed, 7 Jan 2009 08:19:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751941AbZAGNTN (ORCPT ); Wed, 7 Jan 2009 08:19:13 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:35795 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751596AbZAGNTM (ORCPT ); Wed, 7 Jan 2009 08:19:12 -0500 Date: Wed, 7 Jan 2009 14:18:46 +0100 From: Ingo Molnar To: Hugh Dickins Cc: Andi Kleen , Andrew Morton , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [3/5] Mark complex bitops.h inlines as __always_inline Message-ID: <20090107131846.GF3529@elte.hu> References: <200901051236.281008835@firstfloor.org> <20090104233640.6A7453E6653@basil.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 836 Lines: 21 * Hugh Dickins wrote: > Hugh Dickins noticed that released gcc versions building the kernel with > CONFIG_OPTIMIZE_INLINING=y don't inline some of the bitops - sometimes > generating very inefficient pageflag tests, and many instances of > constant_test_bit(). Could you quantify that please? We really dont want to reintroduce __always_inline just for performance / code size reasons. If GCC messes up and makes a larger / more inefficient kernel, GCC will be fixed. CONFIG_OPTIMIZE_INLINING is default-off, so enable it only if it improves your kernel. Ingo -- 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/