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 2868BCA0EFA for ; Sat, 23 Aug 2025 09:00:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 024266B0010; Sat, 23 Aug 2025 05:00:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EF0296B0011; Sat, 23 Aug 2025 05:00:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DB7D38E0018; Sat, 23 Aug 2025 05:00:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C7E826B0010 for ; Sat, 23 Aug 2025 05:00:11 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 5AD6D83EE0 for ; Sat, 23 Aug 2025 09:00:11 +0000 (UTC) X-FDA: 83807425422.13.B7F6047 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf17.hostedemail.com (Postfix) with ESMTP id 91D684000D for ; Sat, 23 Aug 2025 09:00:09 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=rOGkWtsU; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf17.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 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=1755939609; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=A3yFDc62nC30c8ipPORCXl1/TYX9qFzVOp/OlRE3m6M=; b=Hy79MHFa1Gir3LsHfurw5mQ4T8dTv3mKcFiPsRzCmNQskmN0iI+tMPPkTaRduhLly4h1kB Fn8TYerfHJLh4R+fTQmo+q7/mAmvpCQdMaugA7qMV7Y/TOPTsvBlSrVAKfMDOauk3+SE9x CCFzoRTWKjQDNCv9fiozq/KTThlZA4w= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=rOGkWtsU; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf17.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1755939609; a=rsa-sha256; cv=none; b=sy4YuX0c0F1d5BksVum5hHHG6hVVAgw6kP771UBiJnmsVC2dPX5KRkxpse6j/AgEiIX+Tl 4wDChCEE0oGeOysUtEABHxhs/HKoS6tlcomsgJAmi8KEX9scsdneDWAGd/H9Pr7X20kp0w 16MwN9Ar0GI67ZRsjPZrkPTSaAEqiII= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 6ABA25C0FCC; Sat, 23 Aug 2025 09:00:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F35E6C113D0; Sat, 23 Aug 2025 08:59:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755939608; bh=aU4s6rL8qphUf3ASSPtkvFhSbnF7KQL/5p/AkB6ZkD0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rOGkWtsURQmqeVJWZZ8QU1TwZHK57H1RHXwc/i48rhECw+oAVRa4mF0zfqNM3aJ7b K4ufsfNlCAWHsLgknGRRJAM8fAg49ifByU7aHcJpd60KD5n2ftLsVEjekOSHSO2hKf TyNgVi/IP/sZ+Zv1HQC39pwpdaVXtYVat6Ea2uqdZXF6QBRAllDzvBMajMv+E6mXfL wV6BxOvsD2NYhNSk4hF0URYans98VMn0JY+kTDajsHLCy41MHKhsR0ynwpYDfvi23F uDIHwC7s5hdPOSqfKNvqn2djgrkhoLcYMLwZ0RX2xL3FelT1nsv2lD+CEaDl2f3oOX wFjm0sW7YW4bQ== Date: Sat, 23 Aug 2025 11:59:50 +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: Re: [PATCH RFC 10/35] mm/hugetlb: cleanup hugetlb_folio_init_tail_vmemmap() Message-ID: References: <20250821200701.1329277-1-david@redhat.com> <20250821200701.1329277-11-david@redhat.com> <9156d191-9ec4-4422-bae9-2e8ce66f9d5e@redhat.com> <7077e09f-6ce9-43ba-8f87-47a290680141@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7077e09f-6ce9-43ba-8f87-47a290680141@redhat.com> X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 91D684000D X-Stat-Signature: t4af1tzraz6wxomn1dkiyyqxq7saepc8 X-Rspam-User: X-HE-Tag: 1755939609-322452 X-HE-Meta: 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 xWkuk+c6 G8NRbg8h4nTJvvo9OwMLmbO2w2l3KoTn4FgLr8cfjN1Z86bgDXLzEcNbKAJbA74i4omNaspufXPes8jwrWAMGy+DJEWtu8rJFWRX/spLXN2G4vBbAB54uFlAZ8+ooyTCWQmWmOGWqLEg5N11xaVoCY0hlJflRrvR5+ijMdVIGAVzDTRNd1hVIbk+LeQUFG79MhnGdbnMOfo7FFuu5wS2nq0T+iTMbw5CEfM5M1E57O/fYednyrJMUZVwINqzU6CZWLiZePNG2aXHRsYyYHmu/jnjFoRvt3ab2v8bmx6vLyb4k3u+aUVvhyd+vYg2kh763ieHaUjj86MH1FJGDzIxg0cl7DWTDX3xH5GRbdBINptgl144= 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 Fri, Aug 22, 2025 at 08:24:31AM +0200, David Hildenbrand wrote: > On 22.08.25 06:09, Mika Penttilä wrote: > > > > On 8/21/25 23:06, David Hildenbrand wrote: > > > > > All pages were already initialized and set to PageReserved() with a > > > refcount of 1 by MM init code. > > > > Just to be sure, how is this working with MEMBLOCK_RSRV_NOINIT, where MM is supposed not to > > initialize struct pages? > > Excellent point, I did not know about that one. > > Spotting that we don't do the same for the head page made me assume that > it's just a misuse of __init_single_page(). > > But the nasty thing is that we use memblock_reserved_mark_noinit() to only > mark the tail pages ... And even nastier thing is that when CONFIG_DEFERRED_STRUCT_PAGE_INIT is disabled struct pages are initialized regardless of memblock_reserved_mark_noinit(). I think this patch should go in before your updates: diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 753f99b4c718..1c51788339a5 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3230,6 +3230,22 @@ int __alloc_bootmem_huge_page(struct hstate *h, int nid) return 1; } +/* + * Tail pages in a huge folio allocated from memblock are marked as 'noinit', + * which means that when CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled their + * struct page won't be initialized + */ +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT +static void __init hugetlb_init_tail_page(struct page *page, unsigned long pfn, + enum zone_type zone, int nid) +{ + __init_single_page(page, pfn, zone, nid); +} +#else +static inline void hugetlb_init_tail_page(struct page *page, unsigned long pfn, + enum zone_type zone, int nid) {} +#endif + /* Initialize [start_page:end_page_number] tail struct pages of a hugepage */ static void __init hugetlb_folio_init_tail_vmemmap(struct folio *folio, unsigned long start_page_number, @@ -3244,7 +3260,7 @@ static void __init hugetlb_folio_init_tail_vmemmap(struct folio *folio, for (pfn = head_pfn + start_page_number; pfn < end_pfn; pfn++) { struct page *page = pfn_to_page(pfn); - __init_single_page(page, pfn, zone, nid); + hugetlb_init_tail_page(page, pfn, zone, nid); prep_compound_tail((struct page *)folio, pfn - head_pfn); ret = page_ref_freeze(page, 1); VM_BUG_ON(!ret); > Let me revert back to __init_single_page() and add a big fat comment why > this is required. > > Thanks! -- Sincerely yours, Mike.