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 A0653C433F5 for ; Tue, 1 Mar 2022 06:34:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231768AbiCAGeq (ORCPT ); Tue, 1 Mar 2022 01:34:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232692AbiCAGei (ORCPT ); Tue, 1 Mar 2022 01:34:38 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1989B70F4C for ; Mon, 28 Feb 2022 22:33:56 -0800 (PST) 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-out1.suse.de (Postfix) with ESMTPS id D1ACC219A1; Tue, 1 Mar 2022 06:33:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1646116434; 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=wMtsDk3b0hX8joqj3KjxPGJRR7Yf0hzE7vshS8yyLBI=; b=EuQ+dNUmzLWLQ2+RoKuacyeTxk2x3l6+1b1bu6dikA3T1PN3x8RsqQWB6BittnB3bfiJEI v4WZzzEz0KpxToE0u0SnVTlSAlA+vtxgKhAmjUH4ERaSZnStXflBL3N3gTT0oxCXvRySLU XaHYpbCw8WbpCGRYIyTL9SP3jm5d5tc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1646116434; 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=wMtsDk3b0hX8joqj3KjxPGJRR7Yf0hzE7vshS8yyLBI=; b=TwpNU8F9Btq6zmvCfvsQyXENKFfUzvpq8xt418IIijwb9S0HPu89otXrXnEU/u8dp5FY+J 2pEzgU1r9JTSdTCA== 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 E3D14139EF; Tue, 1 Mar 2022 06:33:53 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 8uWmMlG+HWJ6GAAAMHmgww (envelope-from ); Tue, 01 Mar 2022 06:33:53 +0000 Date: Tue, 1 Mar 2022 07:33:52 +0100 From: Oscar Salvador To: Huang Ying Cc: Peter Zijlstra , Mel Gorman , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Feng Tang , Dave Hansen , Baolin Wang , Johannes Weiner , Michal Hocko , Rik van Riel , Yang Shi , Zi Yan , Wei Xu , Shakeel Butt , zhongjiang-ali Subject: Re: [PATCH -V13 3/3] memory tiering: skip to scan fast memory Message-ID: References: <20220221084529.1052339-1-ying.huang@intel.com> <20220221084529.1052339-4-ying.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220221084529.1052339-4-ying.huang@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 21, 2022 at 04:45:29PM +0800, Huang Ying wrote: > If the NUMA balancing isn't used to optimize the page placement among > sockets but only among memory types, the hot pages in the fast memory > node couldn't be migrated (promoted) to anywhere. So it's unnecessary > to scan the pages in the fast memory node via changing their PTE/PMD > mapping to be PROT_NONE. So that the page faults could be avoided > too. > > In the test, if only the memory tiering NUMA balancing mode is enabled, the > number of the NUMA balancing hint faults for the DRAM node is reduced to > almost 0 with the patch. While the benchmark score doesn't change > visibly. > > Signed-off-by: "Huang, Ying" > Suggested-by: Dave Hansen > Tested-by: Baolin Wang > Reviewed-by: Baolin Wang > Acked-by: Johannes Weiner > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Rik van Riel > Cc: Mel Gorman > Cc: Peter Zijlstra > Cc: Yang Shi > Cc: Zi Yan > Cc: Wei Xu > Cc: Oscar Salvador > Cc: Shakeel Butt > Cc: zhongjiang-ali > Cc: linux-kernel@vger.kernel.org > Cc: linux-mm@kvack.org Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE Labs