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 78DB9FED9EF for ; Tue, 17 Mar 2026 18:02:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C449D6B00A4; Tue, 17 Mar 2026 14:02:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BF5166B00A5; Tue, 17 Mar 2026 14:02:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B320A6B00A6; Tue, 17 Mar 2026 14:02:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id A31186B00A4 for ; Tue, 17 Mar 2026 14:02:08 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 513301B7751 for ; Tue, 17 Mar 2026 18:02:08 +0000 (UTC) X-FDA: 84556323936.17.7009C01 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf01.hostedemail.com (Postfix) with ESMTP id 9CE954000C for ; Tue, 17 Mar 2026 18:02:06 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=i7FEkuF1; spf=pass (imf01.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1773770526; 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=5izhRkibXet1pPWeSPaHLG5kIWKTInA1wLq1MnarCh0=; b=i0AGMnoX9Ki36t+stach3bjMTMOqgWGyyp2i5emruXnBb16NVprxK6Xsf5vcESCWOEM/h7 yVkYMSsKuIIQ6MBjetbIJsDc0kbSJewZXa9MgEB3tcwvlHzrUkuSwLQsK8zLf41BpF5k9H z4R9SRY0zohwxinD31wYebw5Jtzl5xQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1773770526; a=rsa-sha256; cv=none; b=YSK4Alsrc9PxEng90lp+Bi7+c73l9M1E4u7y6uhFjjWYZ6EzXl/MteSZYfseS5z/kWbbUT Imak1O0px98yU9CTi1JWg+UsfLg0/FBnD4XPyLCbL2lZWjCGUYSjdyQJb0T/EEWomx/hWy 27FR5iwHXZvWaFNCGgxglmmnhRnyExU= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=i7FEkuF1; spf=pass (imf01.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id DF5EC600AD; Tue, 17 Mar 2026 18:02:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 608ACC4CEF7; Tue, 17 Mar 2026 18:02:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773770525; bh=heRUqLM6WOMvSWX3bQEpAKMgcGGvYDSbOPDUMCKJNCI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i7FEkuF1UZcijSe2FoHeEAXDGEOv5m79j1JHPT7si45zPq5pFrcvqXF3ZpR/Y2+6R YEmQf/TlZmXt92wb+c1wcXSW3fvnwmGlIUtXi8WmX+DevEQDM7sQcG/hJ+q2E18GJ9 EOFoKf1+LWoY/IBb5dLVwiC3lRkHCNxmsBVmzO6Em30pC0cvPS1IcbkFORoIaULmHi y8FwOlfaP26Pxl3nkJ7mpqhv+NCL1WGCUVDYTTd2G6roRJXEC9FjECJiHe5c3BEC/N tv+zBc9Py6+aMTGgTVQvXdRDmdjA5VXLZEov4q7grJU3BN1JGdv6K3OggQCz1osDXO LfCD5xuNMRSPw== Date: Tue, 17 Mar 2026 18:02:00 +0000 From: "Lorenzo Stoakes (Oracle)" To: "David Hildenbrand (Arm)" Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org, Andrew Morton , Oscar Salvador , Axel Rasmussen , Yuanchu Xie , Wei Xu , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko Subject: Re: [PATCH 07/14] mm/bootmem_info: avoid using sparse_decode_mem_map() Message-ID: <22fbfd1f-21aa-43ab-9eb5-28c57972540f@lucifer.local> References: <20260317165652.99114-1-david@kernel.org> <20260317165652.99114-8-david@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260317165652.99114-8-david@kernel.org> X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 9CE954000C X-Stat-Signature: hse1e84uqhjka1nrckfm8sfs17cjwiy4 X-Rspam-User: X-HE-Tag: 1773770526-347235 X-HE-Meta: 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 I1O1RcSD bUJzBN5Aa4J6VCDtylHxZVdOWxc8BxuNWnNilMcbIBLmobf2HuGTi/dGtN7lawGO9gn2+xlNb40xwNMrrefAY0SmxafraCISpVuVXjhQGJswA5z6dFMMNQQgLsQBOmiI8LnnIuXWyDt2lKpjmB/UWCPXxVAOBokyrn27XrohVTTr3MJVQV9QaU2/xKP+5tLR+WQyS9gabfz8x9ulXy09ULZhpZq2LnAxWlBXgCEVJ3twmPIDZvhV7RwaKji9SqEPbuNMTzKVr+w8k1AxbS5Q1BAQrz1ZC/NELJu8d Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Mar 17, 2026 at 05:56:45PM +0100, David Hildenbrand (Arm) wrote: > With SPARSEMEM_VMEMMAP, we can just do a pfn_to_page(). It is not super > clear whether the start_pfn is properly aligned ... so let's just make Maybe worth saying aligned to the start of the section? > sure it is. > > We will soon might try to remove the bootmem info completely, for now, > just keep it working as is. *gasp* > > Signed-off-by: David Hildenbrand (Arm) If it boots ship it, so: Reviewed-by: Lorenzo Stoakes (Oracle) > --- > mm/bootmem_info.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c > index e61e08e24924..3d7675a3ae04 100644 > --- a/mm/bootmem_info.c > +++ b/mm/bootmem_info.c > @@ -44,17 +44,16 @@ static void __init register_page_bootmem_info_section(unsigned long start_pfn) > { > unsigned long mapsize, section_nr, i; > struct mem_section *ms; > - struct page *page, *memmap; > struct mem_section_usage *usage; > + struct page *page; > > + start_pfn = SECTION_ALIGN_DOWN(start_pfn); Yeah SPARSE_VMEMMAP should make it this trivial. > section_nr = pfn_to_section_nr(start_pfn); > ms = __nr_to_section(section_nr); > > - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); > - So this is nice... > if (!preinited_vmemmap_section(ms)) > - register_page_bootmem_memmap(section_nr, memmap, > - PAGES_PER_SECTION); > + register_page_bootmem_memmap(section_nr, pfn_to_page(start_pfn), > + PAGES_PER_SECTION); > > usage = ms->usage; > page = virt_to_page(usage); > -- > 2.43.0 > Cheers, Lorenzo