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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B687C4708F for ; Wed, 2 Jun 2021 19:46:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F93B610A1 for ; Wed, 2 Jun 2021 19:46:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229710AbhFBTro (ORCPT ); Wed, 2 Jun 2021 15:47:44 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:50200 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229489AbhFBTrm (ORCPT ); Wed, 2 Jun 2021 15:47:42 -0400 Received: from imap.suse.de (imap-alt.suse-dmz.suse.de [192.168.254.47]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 5FAF51FD3C; Wed, 2 Jun 2021 19:45:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1622663158; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w/oc7YZVc05AvuONiWEUclRuOrK26WvFpQMDXLOqQ9c=; b=UVlFEgG3USHB6GmF2UBb4j2hKuSpBF1PUQK2tZZvFfFKLvQwzIHFvKOr52vbvFRZJcbqHy /KQU5u0CoKFdVaXQTEkEVTr3HwaKCa3NiIUFmHKYR9XT+7uxKzTthxvH4TLUrYI/alTFMF r/VTLvI8Evom92o9sMeNIvilmjd/bk4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1622663158; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w/oc7YZVc05AvuONiWEUclRuOrK26WvFpQMDXLOqQ9c=; b=c7ryAEr6OsnLL2688tPFa+O88w77ef77Ecd6ZYceexmGhQpm9tnDi1snWK5pTruXCA8tcS A+rmZ9QdxEpbYzCQ== Received: from imap3-int (imap-alt.suse-dmz.suse.de [192.168.254.47]) by imap.suse.de (Postfix) with ESMTP id 531DD118DD; Wed, 2 Jun 2021 19:45:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1622663158; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w/oc7YZVc05AvuONiWEUclRuOrK26WvFpQMDXLOqQ9c=; b=UVlFEgG3USHB6GmF2UBb4j2hKuSpBF1PUQK2tZZvFfFKLvQwzIHFvKOr52vbvFRZJcbqHy /KQU5u0CoKFdVaXQTEkEVTr3HwaKCa3NiIUFmHKYR9XT+7uxKzTthxvH4TLUrYI/alTFMF r/VTLvI8Evom92o9sMeNIvilmjd/bk4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1622663158; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w/oc7YZVc05AvuONiWEUclRuOrK26WvFpQMDXLOqQ9c=; b=c7ryAEr6OsnLL2688tPFa+O88w77ef77Ecd6ZYceexmGhQpm9tnDi1snWK5pTruXCA8tcS A+rmZ9QdxEpbYzCQ== Received: from director2.suse.de ([192.168.254.72]) by imap3-int with ESMTPSA id BIbxE/bft2BXDAAALh3uQQ (envelope-from ); Wed, 02 Jun 2021 19:45:58 +0000 MIME-Version: 1.0 Date: Wed, 02 Jun 2021 21:45:58 +0200 From: Oscar Salvador To: David Hildenbrand Cc: Andrew Morton , Dave Hansen , Michal Hocko , Anshuman Khandual , Vlastimil Babka , Pavel Tatashin , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/3] mm,page_alloc: Use {get,put}_online_mems() to get stable zone's values In-Reply-To: <39473305-6e91-262d-bcc2-76b745a5b14a@redhat.com> References: <20210602091457.17772-1-osalvador@suse.de> <20210602091457.17772-2-osalvador@suse.de> <39473305-6e91-262d-bcc2-76b745a5b14a@redhat.com> User-Agent: Roundcube Webmail Message-ID: X-Sender: osalvador@suse.de Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-06-02 20:37, David Hildenbrand wrote: > Long story short, using get_online_mems() looks wrong. > > Maybe the current lightweight reader/writer protection does serve a > purpose? It was too nice and easy to be true I guess. Yeah, I missed the point that blocking might be an issue here, and hotplug operations can take really long, so not an option. I must have switched my brain off back there, because now it is just too obvious. Then I guwmess that seqlock must stay and the only thing than can go is the pgdat resize lock from the hotplug code. Meh. -- Oscar Salvador SUSE L3