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 EF53FC76195 for ; Wed, 22 Mar 2023 16:18:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229870AbjCVQSN (ORCPT ); Wed, 22 Mar 2023 12:18:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229597AbjCVQSJ (ORCPT ); Wed, 22 Mar 2023 12:18:09 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B6CC422F; Wed, 22 Mar 2023 09:18:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1679501888; x=1711037888; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=GxnyaeprblyISryT2qF5P+Px8gWsxIIA48GZP8Apwvg=; b=OCvBAOQxETqfBEtd8QFhIyMlNvHe4jwP8tRQi8/kRcKU4IkXLNjmyX63 reEsOZh60NvtqqoEYnyEhchK8HdV2svvEQXRz7+j+lQapsq1SOiUx2u0e e9Cic4JTqEDnpR88ASJocMJ6Cssf2EOWLDeA6uZi/0wbOUMbg5fMSxj00 jbMFp4mR2Q/K1Djn6ZdYMYjT7HVX/3rj8BSleKh13JUIxPJnnbO9OCbaD U1fmZyW0R0aUBE3zSE9Dc0qpy/Y731xkP0p7S5VLXRHJ8t/ZUtIeUFBEV 1aFUsK9pbu3l5A6KwZdRsvsnKC4oJqE6LrU8cxMjKBdkbIMzoeKnzU+/M w==; X-IronPort-AV: E=McAfee;i="6600,9927,10657"; a="425547449" X-IronPort-AV: E=Sophos;i="5.98,282,1673942400"; d="scan'208";a="425547449" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Mar 2023 09:16:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10657"; a="675344533" X-IronPort-AV: E=Sophos;i="5.98,282,1673942400"; d="scan'208";a="675344533" Received: from mtfreder-mobl1.amr.corp.intel.com (HELO [10.209.35.23]) ([10.209.35.23]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Mar 2023 09:16:55 -0700 Message-ID: <6320abf6-0898-361b-d5f6-bcc58306f55c@intel.com> Date: Wed, 22 Mar 2023 09:16:55 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [PATCH] mm/slab: Fix undefined init_cache_node_node() for NUMA and !SMP Content-Language: en-US To: Matthew Wilcox , Geert Uytterhoeven Cc: Dave Hansen , Arnd Bergmann , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, John Paul Adrian Glaubitz , linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, Randy Dunlap References: <67261c513706241d479b8b4cf46eb4e6fb0417ba.1679387262.git.geert+renesas@glider.be> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/21/23 09:40, Matthew Wilcox wrote: > On Tue, Mar 21, 2023 at 09:30:59AM +0100, Geert Uytterhoeven wrote: >> -#if (defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)) || defined(CONFIG_SMP) >> +#if defined(CONFIG_NUMA) || defined(CONFIG_SMP) > I'm amused by the thought of CONFIG_NUMA without CONFIG_SMP. > Is it possible to have one node with memory and a single CPU, then > another node with memory and no CPU? It's _possible_ for sure, just unlikely. The most likely place these days is probably a teensy tiny VM that just happens to have some performance-differentiated memory exposed to it for some reason. Maybe it's got a slice of slow PMEM or fast High-Bandwidth memory for whatever reason.