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 5A899C433B4 for ; Sat, 10 Apr 2021 07:26:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DF1AF61165 for ; Sat, 10 Apr 2021 07:26:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF1AF61165 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4EA7F6B006C; Sat, 10 Apr 2021 03:26:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 499DE6B006E; Sat, 10 Apr 2021 03:26:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 33D7B6B0070; Sat, 10 Apr 2021 03:26:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0185.hostedemail.com [216.40.44.185]) by kanga.kvack.org (Postfix) with ESMTP id 167B36B006C for ; Sat, 10 Apr 2021 03:26:39 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id BDE56364C for ; Sat, 10 Apr 2021 07:26:38 +0000 (UTC) X-FDA: 78015624876.10.A20CFCD Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf17.hostedemail.com (Postfix) with ESMTP id 5BE6F40002C2 for ; Sat, 10 Apr 2021 07:26:36 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1618039596; 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=yjZzbPPWgXhfJIj4h7rGByFGwcymMj9q3Ge4BPGca+k=; b=fCSiSkzjE3C7mHOKwprZ06zOxaiXH5i4AebWdZtgLiv0uPW/lAcrcJEj1BIs/nlOoZ74eG f3dq9ng3FJLr294v+ORxAdreMahYyju1zN36zEWvWsgbfzSJmB0Sx4CdXU7Jy+gqgK2OGi qhdKuha/26jglfRF+kl/KTArr7VTPEo= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id BBA12AFDF; Sat, 10 Apr 2021 07:26:36 +0000 (UTC) Date: Sat, 10 Apr 2021 09:25:52 +0200 From: Michal Hocko To: Mel Gorman Cc: Andrew Morton , Linux-MM , LKML , Oscar Salvador , "Michael S. Tsirkin" , David Hildenbrand , Vlastimil Babka , Alexander Duyck , Minchan Kim Subject: Re: [PATCH] mm/memory_hotplug: Make unpopulated zones PCP structures unreachable during hot remove Message-ID: References: <20210409120957.GM3697@techsingularity.net> <20210409134221.GO3697@techsingularity.net> <20210409151259.GP3697@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210409151259.GP3697@techsingularity.net> X-Rspamd-Queue-Id: 5BE6F40002C2 X-Stat-Signature: g4bubkofmsacmpse4p3684a84smbuqz6 X-Rspamd-Server: rspam02 Received-SPF: none (suse.com>: No applicable sender policy available) receiver=imf17; identity=mailfrom; envelope-from=""; helo=mx2.suse.de; client-ip=195.135.220.15 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1618039596-734710 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri 09-04-21 16:12:59, Mel Gorman wrote: [...] > If anything, the minimal "fix" is to simply delete IRQ disable/enable on > the grounds that IRQs protect nothing and assume the existing hotplug > paths guarantees the PCP cannot be used after zone_pcp_enable(). That > should be the case already because all the pages have been freed and > there is nothing to even put into the PCPs but I worried that the PCP > structure itself might still be reachable even if it's useless which is > why I freed the structure once they could not be reached via zonelists. OK. Let's do that for now and I will put a follow up on my todo list. Thanks! -- Michal Hocko SUSE Labs