From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 55CD13DCDA7 for ; Mon, 31 Aug 2026 23:46:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788219966; cv=none; b=PET+OQRYQTH/5Npn+cj+MgY3tBH3FAMGae4hqdq9u0PyTaCqOvH4yufPIhEkiC/GUQd3yqDrPkH1wL9GvBsjXRRZyM+Qs/QTO8aXDyUnrOsmoRkKfAy7dzCbj36EuPKqeAOjowcruSsGADbZh0ZSd6fj1A9xMC6ZyvV8ZuQh2Ao= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788219966; c=relaxed/simple; bh=toNvFVjIUuvbOh55xAH7qUAbqEgIuWqK09DXO0Om7yE=; h=Date:To:From:Subject:Message-Id; b=NjxDW1qVfZFLVdAWylBe/B2ojunubQvv931sBJALxPulHH5qfaA81RnSCiCUpwtmFloLC4DVW0yTmZdUGTN+ktGqBwl0ukzVro/RmjCEEWhnna8qAsVBaknOWLlyC5fxObvo9BhBmK0yppki4wP+cw7N2OwKAz23QCiHg6TSq9Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=NvQeG4tf; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="NvQeG4tf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C97611F00A3D; Mon, 31 Aug 2026 23:46:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788219964; bh=qmTAr/CIOhRD8hTo/r8C6h3gF/hQWz7uloycX6gM5DA=; h=Date:To:From:Subject; b=NvQeG4tfFlb7IsRIRDdu3LIMJksTbwWECLH4FL6bfN/jJLVdsO/RO4fW5aqz3KG74 ISxrcjd2fkvaXG5fHO2hVVols/qquCHIzWW3soLf7Q9jItq4zUUwr13i77TZUarGxN l7K+TrfelTA4Bee3sPXRkwsti+GiqA6HMQU4/e78= Date: Mon, 31 Aug 2026 16:46:04 -0700 To: mm-commits@vger.kernel.org,rppt@kernel.org,muchun.song@linux.dev,mingo@redhat.com,kees@kernel.org,david@kernel.org,dave.hansen@linux.intel.com,bp@alien8.de,balbirs@nvidia.com,arnd@arndb.de,apopple@nvidia.com,lizhe.67@bytedance.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-add-a-set_page_section_from_pfn-helper.patch added to mm-new branch Message-Id: <20260831234604.C97611F00A3D@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: add a set_page_section_from_pfn() helper has been added to the -mm mm-new branch. Its filename is mm-add-a-set_page_section_from_pfn-helper.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-a-set_page_section_from_pfn-helper.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "Li Zhe" Subject: mm: add a set_page_section_from_pfn() helper Date: Mon, 31 Aug 2026 19:16:33 +0800 Callers that want to update section bits from a PFN currently need to open-code: set_page_section(page, pfn_to_section_nr(pfn)); and guard that sequence with #ifdef SECTION_IN_PAGE_FLAGS. Add set_page_section_from_pfn() to wrap that update in one place. When section bits are stored in page flags, the helper derives the section number from the PFN and updates the page flags. Otherwise keep it as a no-op so callers can use one helper without open-coding SECTION_IN_PAGE_FLAGS. Convert set_page_links() to use the new helper so later ZONE_DEVICE fast-path patches can also update section bits without open-coding SECTION_IN_PAGE_FLAGS at each callsite. This keeps the PFN-to-section translation local to the configurations that actually store section bits in struct page flags, and avoids exposing that detail to generic callers. No functional change intended. Link: https://lore.kernel.org/20260831111638.76012-3-lizhe.67@bytedance.com Signed-off-by: Li Zhe Reviewed-by: Mike Rapoport (Microsoft) Acked-by: Muchun Song Reviewed-by: Balbir Singh Cc: Alistair Popple Cc: Arnd Bergmann Cc: "Borislav Petkov (AMD)" Cc: Dave Hansen Cc: David Hildenbrand (Arm) Cc: Ingo Molnar Cc: Kees Cook Signed-off-by: Andrew Morton --- include/linux/mm.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) --- a/include/linux/mm.h~mm-add-a-set_page_section_from_pfn-helper +++ a/include/linux/mm.h @@ -2632,12 +2632,23 @@ static inline void set_page_section(stru page->flags.f |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT; } +static inline void set_page_section_from_pfn(struct page *page, + unsigned long pfn) +{ + set_page_section(page, pfn_to_section_nr(pfn)); +} + static inline unsigned long memdesc_section(const memdesc_flags_t *mdf) { ASSERT_EXCLUSIVE_BITS(mdf->f, SECTIONS_MASK << SECTIONS_PGSHIFT); return (mdf->f >> SECTIONS_PGSHIFT) & SECTIONS_MASK; } #else /* !SECTION_IN_PAGE_FLAGS */ +static inline void set_page_section_from_pfn(struct page *page, + unsigned long pfn) +{ +} + static inline unsigned long memdesc_section(const memdesc_flags_t *mdf) { return 0; @@ -2860,9 +2871,7 @@ static inline void set_page_links(struct { set_page_zone(page, zone); set_page_node(page, node); -#ifdef SECTION_IN_PAGE_FLAGS - set_page_section(page, pfn_to_section_nr(pfn)); -#endif + set_page_section_from_pfn(page, pfn); } /** _ Patches currently in -mm which might be from lizhe.67@bytedance.com are mm-fix-stale-zone_device-refcount-comment.patch mm-add-a-set_page_section_from_pfn-helper.patch mm-add-a-template-based-fast-path-for-zone-device-page-init.patch mm-extend-the-template-fast-path-to-zone-device-compound-tails.patch string-introduce-memcpy_nontemporal.patch mm-use-memcpy_nontemporal-in-zone-device-template-copies.patch x86-string-extend-memcpy_flushcache-fixed-size-fastpaths.patch