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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20BAFC433FE for ; Tue, 7 Dec 2021 10:15:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AC3426B0099; Tue, 7 Dec 2021 05:15:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A72EB6B00AB; Tue, 7 Dec 2021 05:15:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 960E56B00AC; Tue, 7 Dec 2021 05:15:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 870936B0099 for ; Tue, 7 Dec 2021 05:15:26 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 4DDA3181AEF1F for ; Tue, 7 Dec 2021 10:15:16 +0000 (UTC) X-FDA: 78890590632.15.D2C53AA Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf12.hostedemail.com (Postfix) with ESMTP id E414A10000A5 for ; Tue, 7 Dec 2021 10:15:15 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id BDF9421B3E; Tue, 7 Dec 2021 10:15:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1638872114; 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=fmiDXA5yzuOQ3TCOggxW4h5cLqZY2pHWb0txkt/F/pc=; b=IqW/fQHgB6cUG7JdfpLS9iXvR+Oo1okV83ZgupHdvpn+I+hcJpKHI6aU7od55aKm5f943N WV+Lz1y4Cyl/phAHHe7GPybOaW8UpTgXZy274rmRPmQxWRQd3m2FzMGDlLTCQJxIzMhWkC hEgoxQ5Obmjc4x9qiXaBff6qKdJHDXI= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 7BAE5A3B8B; Tue, 7 Dec 2021 10:15:14 +0000 (UTC) Date: Tue, 7 Dec 2021 11:15:13 +0100 From: Michal Hocko To: Yang Shi Cc: Vlastimil Babka , David Hildenbrand , Nico Pache , Linux Kernel Mailing List , Linux MM , Andrew Morton , Shakeel Butt , Kirill Tkhai , Roman Gushchin , Vladimir Davydov , raquini@redhat.com Subject: Re: [RFC PATCH 2/2] mm/vmscan.c: Prevent allocating shrinker_info on offlined nodes Message-ID: References: <51c65635-1dae-6ba4-daf9-db9df0ec35d8@redhat.com> <05157de4-e5df-11fc-fc46-8a9f79d0ddb4@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: kd1si1kexrtb7yiuomgabp7eye7zdxxq Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b="IqW/fQHg"; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf12.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: E414A10000A5 X-HE-Tag: 1638872115-136646 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 Mon 06-12-21 10:26:32, Yang Shi wrote: [...] > But IMHO actually the memory usage should be not that bad for memcg > heavy usecases since there should be not too many "never onlined" > nodes for such workloads? Hardware with very sparse nodes topology are really scarce. More likely on ppc (LPARs) but even then we are talking about really low number of nodes. At least this is my experience. So while the memory wasting is possible it doesn't seem to be a really pressing problem. I would be more careful about a code which scales with MAX_NUMNODES because that can be really large. -- Michal Hocko SUSE Labs