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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 53700E7FDCF for ; Tue, 3 Feb 2026 19:53:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7D4306B0005; Tue, 3 Feb 2026 14:53:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7821B6B0088; Tue, 3 Feb 2026 14:53:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 681C66B0089; Tue, 3 Feb 2026 14:53:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 53B266B0005 for ; Tue, 3 Feb 2026 14:53:39 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id E2F061B2255 for ; 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imf16.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf16.hostedemail.com: domain of benh@kernel.crashing.org designates 63.228.1.57 as permitted sender) smtp.mailfrom=benh@kernel.crashing.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770148417; a=rsa-sha256; cv=none; b=D+rKOzmOVYMGBJPZpAe0D21wzplzI3q89poJy4Xs81j69Fl9kQ1t4Uqx+691xd5COizS7T VrAOWrX2isqe02g3iHM3ADV1cy1nFad2MBxRlO5aeW+WegahAy06Vj2bWCk2MKcUekObcl 65flfamcBrdZZT3WOaBm2t/4Jw8EeXI= Received: from [IPv6:::1] (localhost [127.0.0.1]) by gate.crashing.org (8.18.1/8.18.1/Debian-2) with ESMTP id 613JrT7f3670920; Tue, 3 Feb 2026 13:53:30 -0600 Message-ID: <279931074239b7f3812c4cb3969f887303c8cc26.camel@kernel.crashing.org> Subject: Re: [PATCH] mm: Fix memblock_free_late() when using deferred struct page From: Benjamin Herrenschmidt To: Mike Rapoport Cc: linux-mm@kvack.org Date: Wed, 04 Feb 2026 06:53:29 +1100 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.3-0ubuntu1.1 MIME-Version: 1.0 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 0E4E6180002 X-Stat-Signature: ygjn77q1yi9mcay7q7u74ioipsjicien X-Rspam-User: X-HE-Tag: 1770148415-458001 X-HE-Meta: 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 FhabK0yp 77BxvWsEeJXTvYmghVFCfY3O57IK1BXrvZBxegS9pS3aHVMJut4fCoFnQhW/ass/3IeHVanl2JlH9HkQKgZizXklrjLXZfQ3MWvC4JoZ5Wc8iRKZL7gF7cvO72w== 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, 2026-02-03 at 20:40 +0200, Mike Rapoport wrote: > > =C2=A0void __init memblock_free_pages(struct page *page, unsigned long = pfn, > > - unsigned int > > order) > > + unsigned int order, bool reserved) >=20 > I've been thinking about after more coffee after our chat on IRC, and I > believe we don't need the bool reserved here. >=20 > Since the assumption that memblock_free_late() should be called only afte= r > buddy is initialized, all the reserved pages should have their memmap set= up > with PG_Reserved set. So we can use PageReserved() instead of passing the > boolean. What about free_low_memory_core_early() ->=20 __free_memory_core() -> __free_pages_memory() -> memblock_free_pages() ? I might be missing something but I don't see what would restrict this to the early pre-initialized struct pages other than that early_page_initialised() test, so we can't rely on anything in struct page inside memblock_free_pages(). Cheers, Ben.