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 46672353EEB for ; Fri, 11 Sep 2026 05:15:45 +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=1789103746; cv=none; b=eDFChRV0PEGMx8kWBc/t6bRvGwbTw50UWxfc1pAkLucxBOCQUhsNuvnaD1VHHAgjBUBoYL8bb1mm4TYrpQNuzQwgE3IQobr+iKERfdHYUswsLDK9qjKGSe6dKYzCZL7ExSHdYRk4c3qFyMTMJBaeJH8ywBWYnMz/vx1XzcgyR8k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789103746; c=relaxed/simple; bh=/4174dQRdsUFZq0U39JeZe6oZ9kxeBzIYvseInUe29w=; h=Date:To:From:Subject:Message-Id; b=s57L9ZCvRDbD0EjBnX9dsHSjCRc74MOn9i09a499aLIdkl8Bb+4NqobNmNZyRz6AtqMloZD1UJYnThuQ52P3d3ALNlf3KS0Op02+/JwMKC6oV7TV39Hy51cLEe1hrUxBFMmJP8n2OD90hP4rZEYnWvXZLakyLRm8Oq8lSAyihzk= 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=diGdF6qW; 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="diGdF6qW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD00F1F000FF; Fri, 11 Sep 2026 05:15:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789103745; bh=gQ12j3p2Bu2woBeQypA1o1Rm7jlLGNippw4OPAtmHDY=; h=Date:To:From:Subject; b=diGdF6qWlJJJPoTlalxwXAqafvho2fGv1yt2g0V0tckHzDsUuzCTdMhKUb6Xdtizg DwLXHhqNVHzARZS4m2lcjL/6IHt5JlTDMpMlBWdTymQ/3WiNo1WOpsQOyLJlRj8npq WXEmSuQqQnCNs4L8rRWc/+pHdEkgWT0bFOD935cY= Date: Thu, 10 Sep 2026 22:15:44 -0700 To: mm-commits@vger.kernel.org,songmuchun@bytedance.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-sparse-vmemmap-open-code-init_compound_tail.patch added to mm-new branch Message-Id: <20260911051544.DD00F1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/sparse-vmemmap: open-code init_compound_tail() has been added to the -mm mm-new branch. Its filename is mm-sparse-vmemmap-open-code-init_compound_tail.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-sparse-vmemmap-open-code-init_compound_tail.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: Muchun Song Subject: mm/sparse-vmemmap: open-code init_compound_tail() Date: Fri, 11 Sep 2026 13:02:20 +0800 init_compound_tail() is only used by vmemmap_shared_tail_page(), where the shared tail page setup intentionally passes NULL as the compound head. Keeping this helper in mm/internal.h exposes that special case to the rest of the MM code and can make the NULL head argument look generally valid. Open-code the initialization at the only call site so the special-case use stays local to sparse vmemmap optimization. No functional change intended. Link: https://lore.kernel.org/20260911050228.58884-4-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Qi Zheng Acked-by: David Hildenbrand (Arm) Cc: Jonathan Corbet Cc: Lorenzo Stoakes Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Randy Dunlap Signed-off-by: Andrew Morton --- mm/internal.h | 9 --------- mm/sparse-vmemmap.c | 5 ++++- 2 files changed, 4 insertions(+), 10 deletions(-) --- a/mm/internal.h~mm-sparse-vmemmap-open-code-init_compound_tail +++ a/mm/internal.h @@ -786,15 +786,6 @@ static inline void prep_compound_tail(st VM_WARN_ON_ONCE(tail->private); } -static inline void init_compound_tail(struct page *tail, - const struct page *head, unsigned int order, struct zone *zone) -{ - atomic_set(&tail->_mapcount, -1); - set_page_node(tail, zone_to_nid(zone)); - set_page_zone(tail, zone_idx(zone)); - prep_compound_tail(tail, head, order); -} - #if defined CONFIG_COMPACTION || defined CONFIG_CMA /* --- a/mm/sparse-vmemmap.c~mm-sparse-vmemmap-open-code-init_compound_tail +++ a/mm/sparse-vmemmap.c @@ -189,7 +189,10 @@ struct page __ref *vmemmap_shared_tail_p for (int i = 0; i < PAGE_SIZE / sizeof(struct page); i++) { page = (struct page *)addr + i; mm_zero_struct_page(page); - init_compound_tail(page, NULL, order, zone); + atomic_set(&page->_mapcount, -1); + set_page_node(page, zone_to_nid(zone)); + set_page_zone(page, zone_idx(zone)); + prep_compound_tail(page, NULL, order); } page = virt_to_page(addr); _ Patches currently in -mm which might be from songmuchun@bytedance.com are mm-sparse-relax-struct-mem_section-size-constraints.patch mm-sparse-vmemmap-rename-hvo-order-macros.patch mm-mm_init-skip-initializing-shared-vmemmap-tail-pages.patch mm-sparse-vmemmap-initialize-shared-tail-vmemmap-pages-on-allocation.patch mm-sparse-vmemmap-support-section-based-vmemmap-accounting.patch mm-mm_init-factor-out-pfn_to_zone.patch mm-sparse-vmemmap-move-helpers-ahead-of-future-callers.patch mm-sparse-vmemmap-support-section-based-vmemmap-optimization.patch mm-sparse-initialize-memory-sections-earlier.patch mm-hugetlb-switch-hugetlb-to-section-based-vmemmap-optimization.patch mm-sparse-vmemmap-remove-sparsemem_vmemmap_preinit-support.patch mm-sparse-inline-usemap-allocation-into-sparse_init_nid.patch mm-sparse-remove-section_map_size.patch mm-hugetlb-remove-huge_bootmem_hvo.patch mm-hugetlb-remove-huge_bootmem_cma.patch mm-hugetlb-localize-struct-huge_bootmem_page.patch mm-hugetlb-localize-huge_bootmem_zones_valid.patch mm-sparse-vmemmap-introduce-config_sparsemem_vmemmap_optimization.patch mm-sparse-vmemmap-factor-out-shared-vmemmap-tail-page-allocation.patch mm-sparse-vmemmap-open-code-init_compound_tail.patch mm-sparse-vmemmap-prepare-dax-vmemmap-population-for-compound-page-orders.patch mm-sparse-vmemmap-set-compound-page-order-for-device-dax.patch mm-sparse-vmemmap-switch-device-dax-to-shared-tail-vmemmap-pages.patch mm-sparse-vmemmap-move-vmemmap-optimization-helpers-to-a-public-header.patch powerpc-mm-switch-device-dax-to-shared-tail-vmemmap-pages.patch mm-sparse-vmemmap-drop-the-extra-tail-page-from-device-dax-reservation.patch mm-sparse-vmemmap-drop-unused-section_nr_vmemmap_pages-arguments.patch documentation-mm-update-dax-vmemmap-deduplication-docs.patch