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 D7E33C4321E for ; Wed, 2 Nov 2022 16:22:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231421AbiKBQWm (ORCPT ); Wed, 2 Nov 2022 12:22:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231499AbiKBQVe (ORCPT ); Wed, 2 Nov 2022 12:21:34 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3FF131EC7 for ; Wed, 2 Nov 2022 09:15:21 -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-out1.suse.de (Postfix) with ESMTPS id A42A221E9F; Wed, 2 Nov 2022 16:15:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1667405714; 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=0ltRSvD+MBT0/eZowW+t0lbg4zeEUtzQRQMUxfd+dLc=; b=Ia+9q/A1gQ3ByrTl0c7R3Gle155cWOybT1S1hFJtgXPdv8N2weiwKkF/rr+4o+zEFBwAS+ iV7ltM6DkCGr0GibiXH08/I1Ud3U/nIWKHad3vLvlbFqAOEjJ5TmvZApoY/QhKhiCWiKNn cH1KqunG/vE62dAO92DdeJr4B6BHJd4= 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 871DA139D3; Wed, 2 Nov 2022 16:15:14 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id PkbYHZKXYmNIHAAAMHmgww (envelope-from ); Wed, 02 Nov 2022 16:15:14 +0000 Date: Wed, 2 Nov 2022 17:15:13 +0100 From: Michal Hocko To: Yang Shi Cc: Zach O'Keefe , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: don't warn if the node is offlined Message-ID: References: <20221031183122.470962-1-shy828301@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 02-11-22 09:03:57, Yang Shi wrote: > On Wed, Nov 2, 2022 at 12:39 AM Michal Hocko wrote: > > > > On Tue 01-11-22 12:13:35, Zach O'Keefe wrote: > > [...] > > > This is slightly tangential - but I don't want to send a new mail > > > about it -- but I wonder if we should be doing __GFP_THISNODE + > > > explicit node vs having hpage_collapse_find_target_node() set a > > > nodemask. We could then provide fallback nodes for ties, or if some > > > node contained > some threshold number of pages. > > > > I would simply go with something like this (not even compile tested): > > Thanks, Michal. It is definitely an option. As I talked with Zach, I'm > not sure whether it is worth making the code more complicated for such > micro optimization or not. Removing __GFP_THISNODE or even removing > the node balance code should be fine too IMHO. TBH I doubt there would > be any noticeable difference. I do agree that an explicit nodes (quasi)round robin sounds over engineered. It makes some sense to try to target the prevalent node though because this code can be executed from khugepaged and therefore allocating with a completely different affinity than the original fault. -- Michal Hocko SUSE Labs