From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3264D3A3E68 for ; Mon, 18 May 2026 06:33:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779085985; cv=none; b=n7Qt9xwQg5Q637mRaLEzlXCRchLwJyU5UF5DLdwAZ8gLV+DOgRodGnD1FcfmqwCZ5hmjCtB4Bz+Nnd2sBzQ5H3tPRuyLH2TioBI/n/syaqTLsEYuH2jE3qqQLywFMJQun/3K307KUG9emfhmmQuLst0oWWtoCuqEoOaFSLBxbA0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779085985; c=relaxed/simple; bh=S2sClfE94ut5IkvWCJnZ59x+EGHZ68WYDg9Kv6DqmJQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gKShhA6Tpo1Ow1592njPOfXAM4y1itXYQo16O8nKNqf4tP0qTFMpkhZwc7TUc+mAUNw2eR10oMjelAnhQQ5fS4EF/zzCeLqSYlOQ41n2ED7Klp5Cik5oQx/QMLw7zDFqFOw9ue/gB9/yix7m1jAK43EJeLvop+brmbP2tvXeAxw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A3vbnwtY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A3vbnwtY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67D55C2BCB7; Mon, 18 May 2026 06:32:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779085984; bh=S2sClfE94ut5IkvWCJnZ59x+EGHZ68WYDg9Kv6DqmJQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A3vbnwtY1jjob8OB+9vfc+m48DDecf8TZJhaI+N4f3RrrLwJHp/4Tug1PFa+XpC5F pm2bqTF26qb+29HPgfCbtfimbDEpQ810OrtiD2Ic0aRdx2T+HgPhUZELfT/ucfCXbC 0F5Jig/3OUfsNIff63F1zc0Gq0kwYCUK+E+5X7N7eOfZmxW8oRULsyn56z40rP0xLO SKN+6oE2IOuh1dWyBzSx/ULcbvNfyz0hXDpXbs2MNBXKxWKkiD/yIzkfgf9eW+6xi7 L7xR4PUvkcTl8FGh/hrjI3nJrsXrUuXalZ9bkPlN+LTFscIRfEaDPDJsn8gmRGCHRy T64q9br6Bv4Fg== Date: Mon, 18 May 2026 08:32:53 +0200 From: "Oscar Salvador (SUSE)" To: Muchun Song Cc: Andrew Morton , David Hildenbrand , Muchun Song , Oscar Salvador , Michael Ellerman , Madhavan Srinivasan , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Nicholas Piggin , Christophe Leroy , Ackerley Tng , Frank van der Linden , aneesh.kumar@linux.ibm.com, joao.m.martins@oracle.com, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 08/69] mm/mm_init: Defer sparse_init() until after zone initialization Message-ID: References: <20260513130542.35604-1-songmuchun@bytedance.com> <20260513130542.35604-9-songmuchun@bytedance.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260513130542.35604-9-songmuchun@bytedance.com> On Wed, May 13, 2026 at 09:04:36PM +0800, Muchun Song wrote: > free_area_init() is responsible for initializing pgdat and zone state. > Calling sparse_init() from there mixes in later vmemmap and struct page > setup, which makes the initialization flow less clear. > > Defer sparse_init(), sparse_vmemmap_init_nid_late(), and memmap_init() > until after free_area_init() completes, when zone initialization is fully > done. This keeps free_area_init() focused on zone setup and ensures that > sparse_init() runs with the relevant zone state already available. > > This is also a prerequisite for later hugetlb vmemmap changes that need > zone information during early sparse vmemmap setup. > > Signed-off-by: Muchun Song > Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Oscar Salvador (SUSE) > --- > v1->v2: > - Restore the set_pageblock_order() change suggested by Mike Rapoport > - Add Mike Rapoport's Reviewed-by > --- > mm/mm_init.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/mm/mm_init.c b/mm/mm_init.c > index 12fe21c4e26c..c14491c2dad3 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -1826,7 +1826,6 @@ static void __init free_area_init(void) > bool descending; > > arch_zone_limits_init(max_zone_pfn); > - sparse_init(); > > start_pfn = PHYS_PFN(memblock_start_of_DRAM()); > descending = arch_has_descending_max_zone_pfns(); > @@ -1915,11 +1914,7 @@ static void __init free_area_init(void) > } > } > > - for_each_node_state(nid, N_MEMORY) > - sparse_vmemmap_init_nid_late(nid); > - > calc_nr_kernel_pages(); > - memmap_init(); > > /* disable hash distribution for systems with a single node */ > fixup_hashdist(); > @@ -2691,10 +2686,17 @@ void __init __weak mem_init(void) > > void __init mm_core_init_early(void) > { > + int nid; > + > hugetlb_cma_reserve(); > hugetlb_bootmem_alloc(); > > free_area_init(); > + > + sparse_init(); > + for_each_node_state(nid, N_MEMORY) > + sparse_vmemmap_init_nid_late(nid); > + memmap_init(); > } > > /* > -- > 2.54.0 > -- Oscar Salvador SUSE Labs