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 C2CB0C433F5 for ; Wed, 8 Dec 2021 06:24:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CAAAB6B0083; Wed, 8 Dec 2021 01:19:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C80276B0085; Wed, 8 Dec 2021 01:19:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A39396B0088; Wed, 8 Dec 2021 01:19:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay038.a.hostedemail.com [64.99.140.38]) by kanga.kvack.org (Postfix) with ESMTP id 898BB6B0085 for ; Wed, 8 Dec 2021 01:19:18 -0500 (EST) Received: by unirelay10.hostedemail.com (Postfix, from userid 108) id 17759463; Wed, 8 Dec 2021 06:18:00 +0000 (UTC) Received: by unirelay10.hostedemail.com (Postfix, from userid 108) id C8A93458; Wed, 8 Dec 2021 05:34:09 +0000 (UTC) Received: by unirelay10.hostedemail.com (Postfix, from userid 108) id 6DE17797; Wed, 8 Dec 2021 02:24:59 +0000 (UTC) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 53DBD891 for ; Wed, 8 Dec 2021 01:53:48 +0000 (UTC) X-FDA: 78892955694.08.4D33674 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf18.hostedemail.com (Postfix) with ESMTP id 9DB2D4002087 for ; Wed, 8 Dec 2021 01:53:47 +0000 (UTC) Received: from mail.kernel.org (unknown [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 793ABCE1F7C; Wed, 8 Dec 2021 01:53:43 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 7648E60E98; Wed, 8 Dec 2021 01:53:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1638928421; bh=JIUtT1nVOZt+ipMUhsyNal3eL3AADWDbcDFza2JgQ1E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=s28Ei0baHx4OEp0c39KZjIW9kd2jRsYd1nuE6p2uhpPyY875Rwmt9gMGHFip4PsiZ wFxXFKRDJHz6nC1Ji/OhNvM8x3SGPQx2ZhscHslyJz2U5VGHJ9XZ1pEEZak6wzegbq Dda9bx9PYaFxkUcgSPhSfFVBvvBPfiscQJsbbtmc= Date: Tue, 7 Dec 2021 17:53:38 -0800 From: Andrew Morton To: Nico Pache Cc: Matthew Wilcox , mhocko@suse.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, shakeelb@google.com, ktkhai@virtuozzo.com, shy828301@gmail.com, guro@fb.com, vbabka@suse.cz, vdavydov.dev@gmail.com, raquini@redhat.com, david@redhat.com Subject: Re: [PATCH v2 1/1] mm/vmscan.c: Prevent allocating shrinker_info on offlined nodes Message-Id: <20211207175338.229c52144a67fc1a76b5840c@linux-foundation.org> In-Reply-To: References: <20211207224013.880775-1-npache@redhat.com> <20211207224013.880775-2-npache@redhat.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: iwcgrsg7t4ssf397m7naed5ybbbikdoz Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=s28Ei0ba; spf=pass (imf18.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 9DB2D4002087 X-HE-Tag: 1638928427-560179 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 Tue, 7 Dec 2021 19:25:25 -0500 Nico Pache wrote: > > > On 12/7/21 18:34, Matthew Wilcox wrote: > > On Tue, Dec 07, 2021 at 05:40:13PM -0500, Nico Pache wrote: > >> +++ b/mm/vmscan.c > >> @@ -222,13 +222,16 @@ static int expand_one_shrinker_info(struct mem_cgroup *memcg, > >> int size = map_size + defer_size; > >> > >> for_each_node(nid) { > >> + int tmp = nid; > >> pn = memcg->nodeinfo[nid]; > >> old = shrinker_info_protected(memcg, nid); > >> /* Not yet online memcg */ > >> if (!old) > >> return 0; > >> > >> - new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid); > >> + if(!node_online(nid)) > >> + tmp = numa_mem_id(); > >> + new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, tmp); > >> if (!new) > > > > Why should this be fixed here and not in, say, kvmalloc_node()? > > according to Michal, the caller should be responsible for making sure it is > allocating on a correct node. This avoids adding branches to hot-paths and > wasting cycles. Im not opposed to moving it to kvmalloc_node, but it may result > in masking other issues from other callers. > > Yes, kvmalloc_node(nid) should allocate on `nid', or should fail. A new kvmalloc_try_node() or whatever would express this idea.