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 CA9A137AA8F; Wed, 18 Mar 2026 08:21:05 +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=1773822065; cv=none; b=sQnJvU0RPjpE2qu3J45K16jHFquNn6nqbYFsfO2H6dGCWEyxx+A3O5OhOIZIu96wJjv0i+GM6Cp86lWkLQC3mr/+Zagt6mdFXsoz+y5+bj8jJMnqBGWgB02lIwpTMqS1iURgSrIZTG09Ub89YKVwqt96i+MEtOV7blJUyPhJqK4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773822065; c=relaxed/simple; bh=EA79S28YVeZYHQpiP11IUWT/puy5gsehhvHI39K5RCg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eo+wSjx6MR9m6JCQ4ATVqDJVwIH0h19vdPtEDTLVJ5r8Sl17Cfm3ZMIB9LKjHT6Ja25EvJ+0dU13FAxkUjZzCC/nZEp/MN7CEXZJuekvkmm1WSTy1v4QKliYjndN9bAwXDXgjwgL1nCLix9dINJAMtPwsZcQ8LuyorNeu18eMjY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dopbr9ya; 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="dopbr9ya" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 209E8C19421; Wed, 18 Mar 2026 08:21:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773822065; bh=EA79S28YVeZYHQpiP11IUWT/puy5gsehhvHI39K5RCg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dopbr9yafQgjd3ZiDSZBGn/mrAXnmFXRG0L6C4WtOtDytHn3DWBdmF6Yn8Mb7Yxl0 Ulwn3CljS3CGdFVb0E46PE1tphGRF6X0dV6JP45JIvTBuFdX7043OZKOgisLM7Nw65 vBUyo5nIeT/oKBeASofgIeXFwhVo7Zphn/Kvn9jECbGCGcFM/4ILQm8/XEGMs1/MYY yfB1kz+TUiMTsP8cH+KOvkBB7472VS8/1FEfJCvIsydVdViqkiK0PmcF216+iWLf2k 89atoDsTCZVmnzV/XgzPCJVvcWLEb+VaA5IQGFHZ25s6FteU3fFl3606PSa2MXOsoG ihSq7wogzqhRw== Date: Wed, 18 Mar 2026 10:20:58 +0200 From: Mike Rapoport 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 , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko Subject: Re: [PATCH 08/14] mm/sparse: remove sparse_decode_mem_map() Message-ID: References: <20260317165652.99114-1-david@kernel.org> <20260317165652.99114-9-david@kernel.org> 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: <20260317165652.99114-9-david@kernel.org> On Tue, Mar 17, 2026 at 05:56:46PM +0100, David Hildenbrand (Arm) wrote: > section_deactivate() applies to CONFIG_SPARSEMEM_VMEMMAP only. So we can > just use pfn_to_page() (after making sure we have the start PFN of the > section), and remove sparse_decode_mem_map(). > > Signed-off-by: David Hildenbrand (Arm) Reviewed-by: Mike Rapoport (Microsoft) > --- > include/linux/memory_hotplug.h | 2 -- > mm/sparse.c | 16 +--------------- > 2 files changed, 1 insertion(+), 17 deletions(-) > > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > index e77ef3d7ff73..815e908c4135 100644 > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -308,8 +308,6 @@ extern int sparse_add_section(int nid, unsigned long pfn, > struct dev_pagemap *pgmap); > extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages, > struct vmem_altmap *altmap); > -extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map, > - unsigned long pnum); > extern struct zone *zone_for_pfn_range(enum mmop online_type, > int nid, struct memory_group *group, unsigned long start_pfn, > unsigned long nr_pages); > diff --git a/mm/sparse.c b/mm/sparse.c > index 636a4a0f1199..2a1f662245bc 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -274,18 +274,6 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p > return coded_mem_map; > } > > -#ifdef CONFIG_MEMORY_HOTPLUG > -/* > - * Decode mem_map from the coded memmap > - */ > -struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum) > -{ > - /* mask off the extra low bits of information */ > - coded_mem_map &= SECTION_MAP_MASK; > - return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); > -} > -#endif /* CONFIG_MEMORY_HOTPLUG */ > - > static void __meminit sparse_init_one_section(struct mem_section *ms, > unsigned long pnum, struct page *mem_map, > struct mem_section_usage *usage, unsigned long flags) > @@ -758,8 +746,6 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, > > empty = is_subsection_map_empty(ms); > if (empty) { > - unsigned long section_nr = pfn_to_section_nr(pfn); > - > /* > * Mark the section invalid so that valid_section() > * return false. This prevents code from dereferencing > @@ -778,7 +764,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, > kfree_rcu(ms->usage, rcu); > WRITE_ONCE(ms->usage, NULL); > } > - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); > + memmap = pfn_to_page(SECTION_ALIGN_DOWN(pfn)); > } > > /* > -- > 2.43.0 > -- Sincerely yours, Mike.