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 6A965C4332F for ; Thu, 2 Nov 2023 09:28:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345618AbjKBJ2Y (ORCPT ); Thu, 2 Nov 2023 05:28:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230097AbjKBJ2U (ORCPT ); Thu, 2 Nov 2023 05:28:20 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F902123; Thu, 2 Nov 2023 02:28:14 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id ECE441F896; Thu, 2 Nov 2023 09:28:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1698917292; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=PRT+wqE8dALDjQ1TdgpzGr2kiqVsb3O10DafcXTHWCE=; b=WhSSPRczbxtOiw0KCYhRZXLTwt/LcqWQok4kdcOEeBjXFy269VmoD6h1rMZ4GNmh3rgGpZ yN5cNemN8WhY2y61Fgv+ePyqnNwySMJCB/Sc3vErp/SYyd+xDcjo+ALdkBZv1QLCHYGhxL +YLELvxOfoNWcyKj3S+EJ64IARy86TA= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id A700B138EC; Thu, 2 Nov 2023 09:28:12 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id Jja6JaxrQ2XLaQAAMHmgww (envelope-from ); Thu, 02 Nov 2023 09:28:12 +0000 Date: Thu, 2 Nov 2023 10:28:11 +0100 From: Michal Hocko To: "Huang, Ying" Cc: Johannes Weiner , Gregory Price , linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, weixugc@google.com, apopple@nvidia.com, tim.c.chen@intel.com, dave.hansen@intel.com, shy828301@gmail.com, gregkh@linuxfoundation.org, rafael@kernel.org, Gregory Price Subject: Re: [RFC PATCH v3 0/4] Node Weights and Weighted Interleave Message-ID: References: <20231031003810.4532-1-gregory.price@memverge.com> <20231031152142.GA3029315@cmpxchg.org> <87msvy6wn8.fsf@yhuang6-desk2.ccr.corp.intel.com> <87il6k1y82.fsf@yhuang6-desk2.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87il6k1y82.fsf@yhuang6-desk2.ccr.corp.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 02-11-23 14:11:09, Huang, Ying wrote: > Michal Hocko writes: > > > On Wed 01-11-23 10:21:47, Huang, Ying wrote: > >> Michal Hocko writes: > > [...] > >> > Well, I am not convinced about that TBH. Sure it is probably a good fit > >> > for this specific CXL usecase but it just doesn't fit into many others I > >> > can think of - e.g. proportional use of those tiers based on the > >> > workload - you get what you pay for. > >> > >> For "pay", per my understanding, we need some cgroup based > >> per-memory-tier (or per-node) usage limit. The following patchset is > >> the first step for that. > >> > >> https://lore.kernel.org/linux-mm/cover.1655242024.git.tim.c.chen@linux.intel.com/ > > > > Why do we need a sysfs interface if there are plans for cgroup API? > > They are for different target. The cgroup API proposed here is to > constrain the DRAM usage in a system with DRAM and CXL memory. The less > you pay, the less DRAM and more CXL memory you use. Right, but why the usage distribution requires its own interface and cannot be combined with the access control part of it? -- Michal Hocko SUSE Labs