From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-233.mta0.migadu.com [91.218.175.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 74AED23D28C for ; Fri, 2 Oct 2026 01:49:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.233 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790905800; cv=none; b=LOingIhhe3e3C+FxKBOC0ZFORIVabGg6Bi82bGLvbIBlXkL7Vh7jsDMITGNxjKjT0wQEUKUyiydlCu5226EyOrHjj0ZLEi4icJB3CJ8UxiZ7+L32y3Jd4Vfp+B0citrOQjlOEv8kaejxzEu8Au45BNbU3yGY+a9SVKNBSX1qCpA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790905800; c=relaxed/simple; bh=O/F6AKy+1TPXxN7FZeSSixd6YDpdthmqRGsFYibhu3U=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=XSOYqgGLMB28IL4iiCMMrARrchuIoUQ8Qe+XGPzod/TQZxXOpkiTFPtr4evs+ekJDQ5teuN2tPJqHhZLS633ORfqzKg5pLO2rUSk6wkrQDUi1v4rrrlIQEccrkyrbXaqIWwGHx37igF2wTB+08TfAI7NxLeehfZ6xQMCDLLytAY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=ohcTV+WL; arc=none smtp.client-ip=91.218.175.233 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="ohcTV+WL" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=O/F6AKy+1TPXxN7FZeSSixd6YDpdthmqRGsFYibhu3U=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790905794; v=1; x=1791510594; b=ohcTV+WLBQIjClcA1S1hNHO1DQXU8X2joFAGsI1ThoyMAN+PVq5OqpomUoURl0QZZTMDOsg8 rUTsUjr8j6+/QF/c69xneTs28BVt9aj99XKSrbX2cQn4X8gxKFZI157OdULq5kABQEEY5+ijQ1g unZwtNPkMlkqFp8pYbm9JY2o= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta10.migadu.com with ESMTPS id 7473f29920ffea9f; Fri, 02 Oct 2026 01:49:54 +0000 X-Mizu-Trace-ID: 7473f29920ffea9f X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=utf-8 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.100.1.1.12\)) Subject: Re: [PATCH v3 6/6] mm/mm_init: add zone mismatch warning during page init From: Muchun Song In-Reply-To: Date: Fri, 2 Oct 2026 09:48:42 +0800 Cc: Muchun Song , Madhavan Srinivasan , Andrew Morton , David Hildenbrand , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Ritesh Harjani , Shrikanth Hegde , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Qi Zheng , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Transfer-Encoding: quoted-printable Message-Id: <78D5D6AA-BE36-432C-B0F7-453F93DF18C0@linux.dev> References: <20260929053231.66085-1-songmuchun@bytedance.com> <20260929053231.66085-7-songmuchun@bytedance.com> To: Mike Rapoport X-Mailer: Apple Mail (2.3901.100.1.1.12) > On Oct 1, 2026, at 22:42, Mike Rapoport wrote: >=20 > Hi Muchun, Hi, >=20 > On Tue, Sep 29, 2026 at 01:32:31PM +0800, Muchun Song wrote: >> For vmemmap-optimized sections, tail struct pages may be backed by >> shared vmemmap pages. Those shared pages must carry the same page = zone >> ID as the struct pages initialized for the section. >>=20 >> Warn in __init_single_page() if the shared tail page has a different >> page_zone_id(), which would indicate inconsistent initialization. >>=20 >> Signed-off-by: Muchun Song >> Acked-by: Qi Zheng >> --- >> v3: >> - Collect Acked-by from Qi Zheng >>=20 >> v2: >> - New patch. >> --- >> mm/mm_init.c | 3 +++ >> 1 file changed, 3 insertions(+) >>=20 >> diff --git a/mm/mm_init.c b/mm/mm_init.c >> index 1650d6bc1211..bd02e8d06965 100644 >> --- a/mm/mm_init.c >> +++ b/mm/mm_init.c >> @@ -609,6 +609,9 @@ void __meminit __init_single_page(struct page = *page, unsigned long pfn, >> if (!is_highmem_idx(zone)) >> set_page_address(page, __va(pfn << PAGE_SHIFT)); >> #endif >> + = VM_WARN_ON_ONCE(vmemmap_optimizable_order(pfn_to_section_compound_order(pf= n)) && >> + page_zone_id(page + = VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES) !=3D >> + page_zone_id(page)); >=20 > Hmm, page + VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES is initialized a tad = later > than page so it'll have stale data in the page->flags, won't it? Lance is right. The shared tail struct pages are already initialized by vmemmap_shared_tail_page() during vmemmap population, so they're not = stale. The head 64 struct pages are initialized later =E2=80=94 right here, = after vmemmap population. Thanks, Muchun >=20 >> } >>=20 >> #ifdef CONFIG_NUMA >> --=20 >> 2.54.0 >>=20 >=20 > --=20 > Sincerely yours, > Mike.