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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id F052EC433F5 for ; Wed, 11 May 2022 07:02:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 83AAF6B0073; Wed, 11 May 2022 03:02:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7C3A06B0075; Wed, 11 May 2022 03:02:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 664236B0078; Wed, 11 May 2022 03:02:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 53EA86B0073 for ; Wed, 11 May 2022 03:02:23 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id E0745618CB for ; Wed, 11 May 2022 07:02:19 +0000 (UTC) X-FDA: 79452568398.07.51AEC0B Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf10.hostedemail.com (Postfix) with ESMTP id DC95FC007C for ; Wed, 11 May 2022 07:01:56 +0000 (UTC) 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=4mTV/2QbqZWLgPOWVuiVpIoSDAtrtxN8hCmcU8TRmeg=; b=QFwQGZsV3dczD+XlfgiqYuGLKX /VyHnwZDpeWSzO6tWAjgm1CcoAAU2Rle7YqMDvaPx2RLpGY5Trq/UF+vIbu6Ol9ZNqdz/yVx2PbkM wf+Cd+lVstE0otYE3SInI807gN5jZ1X1BqBpgob6XHQpofscJOEwPinxiYe+B2SwY2FlZAUnJrsvh P0PzKkOjaCMQn8lV1bt2zsn3UB2/FP6g4BM6rPUJvbMrMLDiCBER68A87y0vawa3d9kwTxSEKSr9I xnVN0ZSY0fwTWIn2056OWU0JO34GQ5jJHqYJ3VR/HBsCsdYz/L6c+rET8qQPHo0LJjv8a9dSDI2Xa zlw/vX7A==; 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 1nogMO-005DCv-Hi; Wed, 11 May 2022 07:02:12 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 0EF1F980E3A; Wed, 11 May 2022 09:02:12 +0200 (CEST) Date: Wed, 11 May 2022 09:02:11 +0200 From: Peter Zijlstra To: "Kirill A. Shutemov" Cc: Dave Hansen , Andy Lutomirski , x86@kernel.org, Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFCv2 04/10] x86/mm: Introduce X86_THREAD_LAM_U48 and X86_THREAD_LAM_U57 Message-ID: <20220511070211.GS76023@worktop.programming.kicks-ass.net> References: <20220511022751.65540-1-kirill.shutemov@linux.intel.com> <20220511022751.65540-6-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220511022751.65540-6-kirill.shutemov@linux.intel.com> X-Rspamd-Queue-Id: DC95FC007C X-Stat-Signature: tzr3sfdwdury9frum9a5xxxurgrdfesj X-Rspam-User: Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=QFwQGZsV; spf=none (imf10.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org; dmarc=none X-Rspamd-Server: rspam09 X-HE-Tag: 1652252516-64366 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, May 11, 2022 at 05:27:45AM +0300, Kirill A. Shutemov wrote: > +#define LAM_NONE 0 > +#define LAM_U57 1 > +#define LAM_U48 2 > +#define X86_THREAD_LAM_U48 0x1 > +#define X86_THREAD_LAM_U57 0x2 Seriously pick an order and stick with it. I would suggest keeping the hardware order and then you can do: > +static inline unsigned long lam_to_cr3(u8 lam) > +{ > + switch (lam) { > + case LAM_NONE: > + return 0; > + case LAM_U57: > + return X86_CR3_LAM_U57; > + case LAM_U48: > + return X86_CR3_LAM_U48; > + default: > + WARN_ON_ONCE(1); > + return 0; > + } return (lam & 0x3) << X86_CR3_LAM_U57; > +} > + > +static inline u8 cr3_to_lam(unsigned long cr3) > +{ > + if (cr3 & X86_CR3_LAM_U57) > + return LAM_U57; > + if (cr3 & X86_CR3_LAM_U48) > + return LAM_U48; > + return 0; return (cr3 >> X86_CR3_LAM_U57) & 0x3; > +} and call it a day, or something. I'm still not liking LAM(e), I'm thikning it's going to create more problems than it solves.