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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07078C77B7F for ; Wed, 3 May 2023 19:02:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229738AbjECTCM (ORCPT ); Wed, 3 May 2023 15:02:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229498AbjECTCJ (ORCPT ); Wed, 3 May 2023 15:02:09 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15D2D7D8B for ; Wed, 3 May 2023 12:02:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=0YYQc/fnT1nOd7uUw0b6TC/AbODgNNfUdncisBUND+I=; b=fUfcica9Ew9kItgGFKcp587Hq/ RiMrXeA3W9LDTufGeUHqKWAJfL0hBD+Pz7cfjDqUnHLcVn2YM9LFiP3nXsoKE/X6MqieqEacFjhVD lDyU/yJvJdLzLfZUmMKkUreffDu/a8YtqB29dEtN8zVVrAydNTTxq5xzx+q8nmfzCjSsUqJsoeOfZ uRKaa37sWp9s3u7EuRIECiUneG27Uy1DMCIcaKUXsZGNwM/2rjOJAlbleJGxANqdhl+RF5ajBLKFm vmomxrDj3IDDRx7S5cf7kLcZ51tClwkUdMq7XarLw4iq8t7C4DfyNrkDRUuRlGYcL7WIfMjMPUSD8 VyfVK6Qw==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1puHjZ-000BoW-2T; Wed, 03 May 2023 19:01:50 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id CC4EA3003CF; Wed, 3 May 2023 21:01:47 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id A705024AE4AB5; Wed, 3 May 2023 21:01:47 +0200 (CEST) Date: Wed, 3 May 2023 21:01:47 +0200 From: Peter Zijlstra To: Linus Torvalds Cc: Dave Hansen , "Kirill A. Shutemov" , Dave Hansen , x86@kernel.org, linux-kernel@vger.kernel.org, kirill.shutemov@linux.intel.com Subject: Re: [GIT PULL] x86/mm for 6.4 Message-ID: <20230503190147.GA1719388@hirez.programming.kicks-ass.net> References: <20230429003822.n3mglslg666j3npp@box.shutemov.name> <641a9348-a052-6bb5-e6c7-64acb6405328@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 03, 2023 at 10:54:38AM -0700, Linus Torvalds wrote: > On Wed, May 3, 2023 at 9:38 AM Linus Torvalds > wrote: > > > > So I'm going to just remove the 'sign' games entirely. They are > > completely broken in 'untagged_addr_remote()', they _used_ to be > > completely broken in 'untagged_addr()', and it looks like it's all > > unnecessary. > > Ok, I've pushed out my changes to the 'x86-uaccess-cleanup' branch. > > I think it's all good, but it would be really nice to hear it's been > tested on a setup that actually has LAM (simulator? or maybe there is > actual hw inside Intel) > > And any other commentary is appreciated, Looks sane from a first reading. But I'll try and have another look tomorrow. Also per how 2s complement is constructed 0 has to be in the positive space for it to be 'half'. Also, typically 0 is included in N and the traditional 'positive integers' set is then written as N \ {0}, but that's somewhat modern and a lot of variation exists -- although typically books tend to specify where they stand on that issue. I suppose that's a very long winded way of saying, that yes, ofcourse 0 is a positive number :-)