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 0BD9CCA0FE8 for ; Mon, 25 Aug 2025 16:58:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4522C8E0057; Mon, 25 Aug 2025 12:58:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 402C08E0038; Mon, 25 Aug 2025 12:58:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2F1C58E0057; Mon, 25 Aug 2025 12:58:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 141E28E0038 for ; Mon, 25 Aug 2025 12:58:31 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id DF1F61DD76A for ; Mon, 25 Aug 2025 16:58:30 +0000 (UTC) X-FDA: 83815888380.17.FCA2A95 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf05.hostedemail.com (Postfix) with ESMTP id 220C010000B for ; Mon, 25 Aug 2025 16:58:28 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=K8EPeL9r; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf05.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756141109; a=rsa-sha256; cv=none; b=uIGNgXocRPQT3a8XudfuaiQEYr6SqtF67ozFXRxPmfau3L2bdN/fjG1BuSpZDVTrehWi0Q /wp6QSNhGxCf6vgtHzBl/DX+wO/aK1O0OPMIpE8Nhzo8D3/iRWGv4SwHHR2sMZPcZ6V6xt h+xXagY3VaUu2JmDzZrejuZs+qYIrlM= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=K8EPeL9r; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf05.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756141109; 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=r72jr2fb8G7h/yyetD/U7kOQIEeXffCRdNoOrm+lHkk=; b=qKiTbGiT0BR8+ek8BCqhGp+8JeRiXYh0FqlqjdpvkV5z439w+0KCaFFGBcOvd8iJAhLbSI sVQAn1ULuWYEliuglTpE3eXSAYUmBH7hdpO9kP2h8gV6CA+kBosFPrm1g+/oR8lTHPuq5t kq4qn4fE7v29/7YSxLuf7p2ecU2Yt/s= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id C4B8D43E7E; Mon, 25 Aug 2025 16:58:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF37AC4CEED; Mon, 25 Aug 2025 16:58:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756141107; bh=5Xs4ClQrBNPUK24yQ8tvJo62CGzQ+OUCbyk/7pv7K6g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=K8EPeL9rFMK2+nBscZ78BHN9AXOnwLlio8wCQA9T4HPI2M7JTseek460vnzI7LqJC TDu4NzXeMpXS8jhUa/iSAcIvRfHFDSrWxcvq7/PwB+bucaEQsHAodSxeBqU3oHbYQw JfnmUaXpTgDVr5GNOQRbyvPuO31dhRIGQUncZS3uv95CJi5KIRjBjS37ASsfqMbjJV FaVoAzebuKQA21fTHdob2rVKAkh6oJNsI5NIl49si6OGRBanVCOrvFPYRUxz3E2h7U H5t70EO0n4A9bkEljsMG6VtFtoS+dKBxf5ZFl9Bmc3Iax0SvbwLHZzXF+Oj3qlKigt vsahqKXPodl2Q== Date: Mon, 25 Aug 2025 19:58:10 +0300 From: Mike Rapoport To: David Hildenbrand Cc: Mika =?iso-8859-1?Q?Penttil=E4?= , linux-kernel@vger.kernel.org, Alexander Potapenko , Andrew Morton , Brendan Jackman , Christoph Lameter , Dennis Zhou , Dmitry Vyukov , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, iommu@lists.linux.dev, io-uring@vger.kernel.org, Jason Gunthorpe , Jens Axboe , Johannes Weiner , John Hubbard , kasan-dev@googlegroups.com, kvm@vger.kernel.org, "Liam R. Howlett" , Linus Torvalds , linux-arm-kernel@axis.com, linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-ide@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, Lorenzo Stoakes , Marco Elver , Marek Szyprowski , Michal Hocko , Muchun Song , netdev@vger.kernel.org, Oscar Salvador , Peter Xu , Robin Murphy , Suren Baghdasaryan , Tejun Heo , virtualization@lists.linux.dev, Vlastimil Babka , wireguard@lists.zx2c4.com, x86@kernel.org, Zi Yan Subject: update kernel-doc for MEMBLOCK_RSRV_NOINIT (was: Re: [PATCH RFC 10/35] mm/hugetlb: cleanup hugetlb_folio_init_tail_vmemmap()) Message-ID: References: <9156d191-9ec4-4422-bae9-2e8ce66f9d5e@redhat.com> <7077e09f-6ce9-43ba-8f87-47a290680141@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 220C010000B X-Stat-Signature: 8rz9ax1tthc7qxajwu9681x3x14m7eaz X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1756141108-408037 X-HE-Meta: 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 xssMHdQ5 CgRl9o6Pov/dwhgijR9m96lGYxOEG4MMHbu7c50uUR/rtSUUrJQD1rzghtHs4I6QKHwt95gnlF6xMufFNrt6em1GPHU0KaAmdaijZq4RJM5FK8D1MlqOw0XLyAJzCYQcnO1gVWabUMQljqjLG0ChmGJN07x4MFZL3AFJAJPKAZe3l1sxhqsc55GMHK1ugWVvc3l5ddbHCiOrmwntKbbou+3RFq7vRa8fxJt/rp4sn/X133QKD4GMPgudoZ/+C16UHwsMcjhpdmcJO9J4D7iCRdt+Ef8UqSKtz8Qp6/jO34TTx/YY5raETGoBEVA== 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 Mon, Aug 25, 2025 at 06:23:48PM +0200, David Hildenbrand wrote: > > I don't quite understand the interaction with PG_Reserved and why anybody > using this function should care. > > So maybe you can rephrase in a way that is easier to digest, and rather > focuses on what callers of this function are supposed to do vs. have the > liberty of not doing? How about diff --git a/include/linux/memblock.h b/include/linux/memblock.h index b96746376e17..fcda8481de9a 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -40,8 +40,9 @@ extern unsigned long long max_possible_pfn; * via a driver, and never indicated in the firmware-provided memory map as * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in the * kernel resource tree. - * @MEMBLOCK_RSRV_NOINIT: memory region for which struct pages are - * not initialized (only for reserved regions). + * @MEMBLOCK_RSRV_NOINIT: reserved memory region for which struct pages are not + * fully initialized. Users of this flag are responsible to properly initialize + * struct pages of this region * @MEMBLOCK_RSRV_KERN: memory region that is reserved for kernel use, * either explictitly with memblock_reserve_kern() or via memblock * allocation APIs. All memblock allocations set this flag. diff --git a/mm/memblock.c b/mm/memblock.c index 154f1d73b61f..46b411fb3630 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1091,13 +1091,20 @@ int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size) /** * memblock_reserved_mark_noinit - Mark a reserved memory region with flag - * MEMBLOCK_RSRV_NOINIT which results in the struct pages not being initialized - * for this region. + * MEMBLOCK_RSRV_NOINIT + * * @base: the base phys addr of the region * @size: the size of the region * - * struct pages will not be initialized for reserved memory regions marked with - * %MEMBLOCK_RSRV_NOINIT. + * The struct pages for the reserved regions marked %MEMBLOCK_RSRV_NOINIT will + * not be fully initialized to allow the caller optimize their initialization. + * + * When %CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, setting this flag + * completely bypasses the initialization of struct pages for such region. + * + * When %CONFIG_DEFERRED_STRUCT_PAGE_INIT is disabled, struct pages in this + * region will be initialized with default values but won't be marked as + * reserved. * * Return: 0 on success, -errno on failure. */ > -- > Cheers > > David / dhildenb > -- Sincerely yours, Mike.