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 8F57BC28B28 for ; Wed, 12 Mar 2025 05:22:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 39D76280003; Wed, 12 Mar 2025 01:22:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 34E16280001; Wed, 12 Mar 2025 01:22:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 216BF280003; Wed, 12 Mar 2025 01:22:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 05D89280001 for ; Wed, 12 Mar 2025 01:22:55 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 365B0B7530 for ; Wed, 12 Mar 2025 05:22:56 +0000 (UTC) X-FDA: 83211754752.02.A2538F3 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf08.hostedemail.com (Postfix) with ESMTP id 7CC64160002 for ; Wed, 12 Mar 2025 05:22:54 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=QJLi4J2x; spf=pass (imf08.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741756974; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=KzbXFMV786eVJq7FLnO8K0MeCoB9B3Kay5zlGk5e+v4=; b=xSiLv1esrSixKlVkNAATiCnjxTxGtYfo5KDsi9tL5XHdi1T5AJfvZ7PAtA1q91Kfe9nlni JncMY0iNMHTlQ9bWlzD2iUVPkqGIfSEvqPCGk6jE0EN/+6nlW5/gXUFErqmZ9VYP74zP/+ VKS6XUEfQgRGgNJtX+bQzcv1xOlVYBk= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=QJLi4J2x; spf=pass (imf08.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741756974; a=rsa-sha256; cv=none; b=tr9jk1XFu/EXv5/WlHE4jzhjknyD1zCqvIg+VK1tuoIGy5jLWpUL4L2Tr20h+jAL5WFazu M0OK44a8HVFmsB00s5/OS1d+dPLKvrj9Y+fFV4dYzEjMe6WgxPyw6QtbwZgm6dS6O7+IhN LE8HhR0CtWcOJz0o1MmHeO1WlcFug4E= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 7568B5C00DE; Wed, 12 Mar 2025 05:20:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02259C4CEE3; Wed, 12 Mar 2025 05:22:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741756973; bh=MX9hYn1R3GA95hwjkNf4w1qXBrTQlxYINeZ/wUzSEoE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QJLi4J2x24E0OjEkqPuO1haW7AHR6DGYru/D1S6ptUFAvXbp8in4nAmGLKr2pOUg7 Z1J0plTI95OI5ebPj6ikSorMqIzs0QJEWTxu/wtkocmIXt2J7MukuodYaHq6AaCIbe jjFPMJdAZgZHtTYJTVSEXf37NEP0oaHu8LCtGp5IhwCZJzWVAmRXwqDqvijPZiTaRi K6OyYLahKkCniytb67C66EIRERf+81EC2yi2+TksactycCQF2RWhWrZFsp/iCcTi9a JhFxt5gH9x92KyCsM0hxvS6FcRsy7ygG829sFZf8gGkI7EAo1Jz2UNTLaIb/g4ITvo 6pD0U/hv4Ofow== Date: Wed, 12 Mar 2025 07:22:30 +0200 From: Mike Rapoport To: Wei Yang Cc: linux-kernel@vger.kernel.org, Alexander Graf , Andrew Morton , Andy Lutomirski , Anthony Yznaga , Arnd Bergmann , Ashish Kalra , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Dave Hansen , David Woodhouse , Eric Biederman , Ingo Molnar , James Gowans , Jonathan Corbet , Krzysztof Kozlowski , Mark Rutland , Paolo Bonzini , Pasha Tatashin , "H. Peter Anvin" , Peter Zijlstra , Pratyush Yadav , Rob Herring , Rob Herring , Saravana Kannan , Stanislav Kinsburskii , Steven Rostedt , Thomas Gleixner , Tom Lendacky , Usama Arif , Will Deacon , devicetree@vger.kernel.org, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Subject: Re: [PATCH v4 02/14] memblock: add MEMBLOCK_RSRV_KERN flag Message-ID: References: <20250206132754.2596694-1-rppt@kernel.org> <20250206132754.2596694-3-rppt@kernel.org> <20250218155004.n53fcuj2lrl5rxll@master> <20250223002229.xuk6xlp23zr72hkc@master> <20250310095124.pa7dwgqhxglqrfes@master> <20250311134126.xfjdq6sq7jtcotck@master> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250311134126.xfjdq6sq7jtcotck@master> X-Rspam-User: X-Rspamd-Queue-Id: 7CC64160002 X-Rspamd-Server: rspam08 X-Stat-Signature: 96wmh67hkqidwjewo6fnonqik3tbcj6f X-HE-Tag: 1741756974-606415 X-HE-Meta: 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 3/olaoMY JgKbagtJuOlZnf1iIpSsEtB9u8W/5GJNdOuus6zuTB64dhBjPfYVWWrxNIL9GT2PT2xhgvFXz2jFOM6wuij13EbUORlPFt040Fzn4jLGs80FTg8jsC59Oasb74TtQyC6NK8uMBmUbfrx5HNwE9x7k/LaUNAgzZLtEiKVAmDlBju22PiqnC6AmBPQ6aYZY0alkKXsgavyF3LjAScygp59ZKZ+RutkKa10aHnYnLyjQrfCgQhMgbdM+jgoONOfco+c3icfiLro4s59GaNrApvLlm2j7NoMjEkUp5LYiLs4mPQwm9e3oj+EsPFsX6ErK/3+egJVdfoUfpNOStV9N8s+kjiTgt4XavCTwhc7WCqI/IEV0kxz6NFPK1F9hvm/W3jegUdob 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: List-Subscribe: List-Unsubscribe: On Tue, Mar 11, 2025 at 01:41:26PM +0000, Wei Yang wrote: > On Tue, Mar 11, 2025 at 07:27:23AM +0200, Mike Rapoport wrote: > >> >> > >> > > >> >I took another look into this commit. There maybe a very corner case in which > >> >will leave a reserved region with no nid set. > >> > > >> >memmap_init_reserved_pages() > >> > for_each_mem_region() { > >> > ... > >> > memblock_set_node(start, end, &memblock.reserved, nid); > >> > } > >> > > >> >We leverage the iteration here to set nid to all regions in memblock.reserved. > >> >But memblock_set_node() may call memblock_double_array() to expand the array, > >> >which may get a range before current start. So we would miss to set the > >> >correct nid to the new reserved region. > >> > > >> >I have tried to create a case in memblock test. This would happen when there > >> >are 126 memblock.reserved regions. And the last region is across the last two > >> >node. > >> > > >> >One way to fix this is compare type->max in memblock_set_node(). Then check > >> >this return value in memmap_init_reserved_pages(). If we found the size > >> >changes, repeat the iteration. > >> > > >> >But this is a very trivial one, not sure it worth fix. > >> > > >> > >> Hi, Mike > >> > >> I have done a user space test which shows we may have a chance to leave a > >> region with non-nid set. > >> > >> Not sure you are ok with my approach of fixing. > > > >Wouldn't it be better to check for a change in reserved.max in > >memmap_init_reserved_pages()? > > > > Sounds better. > > Previously I thought we need to hide detail from user, but actually it is > already in memblock.c :-) > > If you agree, I would like to prepare a fix. Sure :) > >> -- > >> Wei Yang > >> Help you, Help me -- Sincerely yours, Mike.