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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 999DCC433DB for ; Wed, 6 Jan 2021 19:09:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2C8FF2311B for ; Wed, 6 Jan 2021 19:09:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C8FF2311B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7841E6B02BE; Wed, 6 Jan 2021 14:09:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 732886B02C0; Wed, 6 Jan 2021 14:09:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 648976B02C1; Wed, 6 Jan 2021 14:09:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0242.hostedemail.com [216.40.44.242]) by kanga.kvack.org (Postfix) with ESMTP id 4FDC16B02BE for ; Wed, 6 Jan 2021 14:09:27 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 140E28245571 for ; Wed, 6 Jan 2021 19:09:27 +0000 (UTC) X-FDA: 77676288774.08.blade40_5d05d8b274e4 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id E72951819E773 for ; Wed, 6 Jan 2021 19:09:26 +0000 (UTC) X-HE-Tag: blade40_5d05d8b274e4 X-Filterd-Recvd-Size: 1738 Received: from gentwo.org (gentwo.org [3.19.106.255]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Wed, 6 Jan 2021 19:09:26 +0000 (UTC) Received: by gentwo.org (Postfix, from userid 1002) id 02B783F551; Wed, 6 Jan 2021 19:09:25 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 007B53F550; Wed, 6 Jan 2021 19:09:25 +0000 (UTC) Date: Wed, 6 Jan 2021 19:09:25 +0000 (UTC) From: Christoph Lameter X-X-Sender: cl@www.lameter.com To: Vlastimil Babka cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Pekka Enberg , David Rientjes , Joonsoo Kim , Vladimir Davydov , Qian Cai , David Hildenbrand , Michal Hocko Subject: Re: [RFC 0/3] mm, slab, slub: remove cpu and memory hotplug locks In-Reply-To: <20210106174029.12654-1-vbabka@suse.cz> Message-ID: References: <20210106174029.12654-1-vbabka@suse.cz> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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 Wed, 6 Jan 2021, Vlastimil Babka wrote: > rather accept some wasted memory in scenarios that should be rare anyway (full > memory hot remove), as we do the same in other contexts already. It's all RFC > for now, as I might have missed some reason why it's not safe. Looks good to me. My only concern is the kernel that has hotplug disabled. Current code allows the online/offline checks to be optimized away. Can this patch be enhanced to do the same?