From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4D90C433EF for ; Tue, 9 Nov 2021 22:11:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A99B611ED for ; Tue, 9 Nov 2021 22:11:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244883AbhKIWOa (ORCPT ); Tue, 9 Nov 2021 17:14:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235998AbhKIWO3 (ORCPT ); Tue, 9 Nov 2021 17:14:29 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A359EC061764; Tue, 9 Nov 2021 14:11:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2dap8ibmURuYipx1vLLUctBMVi/xPDv6Pvkxjpj+KQk=; b=jDwM44R26h1wqDoYMo8Vx+RY2r z7ruLPduz90bNV8IoPbEPdlXjXNgCP7sbxxWTkPuATS8cgjehNyuNqNYk3YWMIy6ANFy2RgdeElBQ j/8NF5S3gvf0vJtqcbme23QFCmjsj1xxiTFPPZuKdXPoVmSIFt3JdBOTrUqcPd2XUNIUkP0gyQjtc pKoIJMvdyMH3qtocUBCPTdLib50rqhbN9HN4IoknBjq9YYZO+IZhOTPMXOG9uXUJtjYdjgKZFy/Ro f9F/W9EX22y8VmQIoIaunX6Pyvtu5p9HCsy3O7K/FAQirVPTBlCMBB9nYRF2LxeXwF8cL4wCt7fuw Z36CAVHw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mkZL0-001Nm4-Eh; Tue, 09 Nov 2021 22:11:31 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 8E43A9862D2; Tue, 9 Nov 2021 23:11:30 +0100 (CET) Date: Tue, 9 Nov 2021 23:11:30 +0100 From: Peter Zijlstra To: Nick Desaulniers Cc: Bill Wendling , Josh Poimboeuf , x86@kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, dvyukov@google.com, seanjc@google.com, pbonzini@redhat.com, mbenes@suse.cz, llvm@lists.linux.dev, linux-toolchains@vger.kernel.org Subject: Re: [PATCH 20/22] x86,word-at-a-time: Remove .fixup usage Message-ID: <20211109221130.GA174703@worktop.programming.kicks-ass.net> References: <20211105171023.989862879@infradead.org> <20211105171821.654356149@infradead.org> <20211108164711.mr2cqdcvedin2lvx@treble> <20211109212116.GW174703@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 09, 2021 at 01:25:47PM -0800, Nick Desaulniers wrote: > On Tue, Nov 9, 2021 at 1:21 PM Peter Zijlstra wrote: > > > > On Tue, Nov 09, 2021 at 12:59:12PM -0800, Bill Wendling wrote: > > > > > > Adding attributes to labels shouldn't be difficult, as you mention. In > > > the case of cold/hot, it's adjusting some of the metadata that already > > > exists on some basic blocks. It might be enough to allow the normal > > > block placement algorithms to move the hot and cold blocks around for > > > us. The question becomes how many attributes does GCC allow on labels? > > > > I'm aware of 3: unused, hot, cold. Also: > > > > https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html > > Re: unused: > Being able to selectively disable -Wunused-label via > __attribute__((unused)); seems useful, too. kernel/sched/fair.c:done: __maybe_unused; Yes it is ;-)