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 D43783ED5A1 for ; Mon, 21 Sep 2026 22:49:40 +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=1790030982; cv=none; b=idAyZ8to/V8jVaYV4C+HtNurjIdzg9u+ijzSDItzR/hVMtSpUm9/ZW9klsuAU/UEOs9JaQEWR2DhWCtB8XAJ5Z4iA1oAjk9Tg6dp6/Gf6ib6898JBEcSLVULpfkxvcvhHlRlf+TgSOoMmQeSNINrw5iPKEjOpQeJPmkNlUikik8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790030982; c=relaxed/simple; bh=GM0RrFL0/YmQoqdbmQhbyHwMU6nPYuacSAJ6qDnHy2E=; h=Date:To:From:Subject:Message-Id; b=aAcZvZzfIqSVw2ozQqd9jlIIkU5IbMOGULbUFKZhdWdFvp6tTiVWfJPlSX5OTC+5tOIfWlTK3IlyApd/R54Q/B+kancp+twnArh1LFgDHNFF93LNYUxueSv2eywQQA/7RnCgriC1K5NVuvjn7T8K4NHrJUJLLHYzcYpK6hvvu4Y= 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=AmCNpSNr; 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="AmCNpSNr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 468A81F00893; Mon, 21 Sep 2026 22:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1790030980; bh=DMo6sLmgle045h7hR+uSrs7o0YLFrfSQ3Z3wdfB6hyI=; h=Date:To:From:Subject; b=AmCNpSNrJmELL0w3LSI/+ig9a9ds4P6pZLmK2OdlODAMC0GkJNxIi83rVPo8YoT1L pq5XFbgRg3S0cioz5DU6aJ+X6kBPsRfuJaDtw+RX8c1DrUkW+LZEoGK9GU9sGh/qqW srJo/cPuIQRgp2nTPWv3uB7x6puvq+coQ10wa1vk= Date: Mon, 21 Sep 2026 15:49:39 -0700 To: mm-commits@vger.kernel.org,david@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr.patch added to mm-new branch Message-Id: <20260921224940.468A81F00893@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: rename __highest_present_section_nr to __highest_used_section_nr has been added to the -mm mm-new branch. Its filename is mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr.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: "David Hildenbrand (Arm)" Subject: mm/sparse: rename __highest_present_section_nr to __highest_used_section_nr Date: Mon, 21 Sep 2026 21:58:58 +0200 In preparation for getting rid of SECTION_MARKED_PRESENT, rename __highest_present_section_nr and clarify the comment. Link: https://lore.kernel.org/20260921-b4-sparsemem_cleanups-v2-6-54d81d65e125@kernel.org Signed-off-by: David Hildenbrand (Arm) Signed-off-by: Andrew Morton Acked-by: Oscar Salvador Reviewed-by: Lorenzo Stoakes (ARM) Reviewed-by: Mike Rapoport (Microsoft) Cc: Liam R. Howlett Cc: Vlastimil Babka Cc: Suren Baghdasaryan Cc: Michal Hocko Cc: Kairui Song Cc: Qi Zheng Cc: Shakeel Butt Cc: Barry Song Cc: Axel Rasmussen Cc: Yuanchu Xie Cc: Wei Xu Cc: Baoquan He Cc: Baolin Wang Cc: Brendan Jackman Cc: Johannes Weiner Cc: Zi Yan Cc: Jan Kiszka Cc: Kieran Bingham Cc: Greg Kroah-Hartman Cc: Rafael J. Wysocki Cc: Danilo Krummrich --- include/linux/mmzone.h | 6 +++--- mm/compaction.c | 2 +- mm/sparse.c | 12 ++++-------- mm/sparse.h | 4 ++-- 4 files changed, 10 insertions(+), 14 deletions(-) --- a/include/linux/mmzone.h~mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr +++ a/include/linux/mmzone.h @@ -2181,7 +2181,7 @@ static inline struct mem_section *__pfn_ return __nr_to_section(pfn_to_section_nr(pfn)); } -extern unsigned long __highest_present_section_nr; +extern unsigned long __highest_used_section_nr; static inline int subsection_map_index(unsigned long pfn) { @@ -2280,7 +2280,7 @@ static inline unsigned long first_valid_ rcu_read_lock_sched(); - while (nr <= __highest_present_section_nr && pfn < end_pfn) { + while (nr <= __highest_used_section_nr && pfn < end_pfn) { struct mem_section *ms = __pfn_to_section(pfn); if (valid_section(ms) && @@ -2335,7 +2335,7 @@ static inline int pfn_in_present_section static inline unsigned long next_present_section_nr(unsigned long section_nr) { - while (++section_nr <= __highest_present_section_nr) { + while (++section_nr <= __highest_used_section_nr) { if (present_section_nr(section_nr)) return section_nr; } --- a/mm/compaction.c~mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr +++ a/mm/compaction.c @@ -216,7 +216,7 @@ static unsigned long skip_offline_sectio if (online_section_nr(start_nr)) return 0; - while (++start_nr <= __highest_present_section_nr) { + while (++start_nr <= __highest_used_section_nr) { if (online_section_nr(start_nr)) return section_nr_to_pfn(start_nr); } --- a/mm/sparse.c~mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr +++ a/mm/sparse.c @@ -164,15 +164,11 @@ static void __init mminit_validate_memmo } /* - * There are a number of times that we loop over NR_MEM_SECTIONS, - * looking for section_present() on each. But, when we have very - * large physical address spaces, NR_MEM_SECTIONS can also be - * very large which makes the loops quite long. - * - * Keeping track of this gives us an easy way to break out of - * those loops early. + * Looping over all possible memory sections is expensive, especially if + * NR_MEM_SECTIONS is large but only a fraction is actually used. Keep track of + * the highest section number we ever used. */ -unsigned long __highest_present_section_nr; +unsigned long __highest_used_section_nr; static inline unsigned long first_present_section_nr(void) { --- a/mm/sparse.h~mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr +++ a/mm/sparse.h @@ -44,8 +44,8 @@ static inline void sparse_init_one_secti static inline void __section_mark_present(struct mem_section *ms, unsigned long section_nr) { - if (section_nr > __highest_present_section_nr) - __highest_present_section_nr = section_nr; + if (section_nr > __highest_used_section_nr) + __highest_used_section_nr = section_nr; ms->section_mem_map |= SECTION_MARKED_PRESENT; } _ Patches currently in -mm which might be from david@kernel.org are maintainers-split-up-memory-management-memory-policy-and-migration.patch maintainers-move-memory-tiering-under-memory-management-numa-placement.patch maintainers-make-gregory-a-co-maintainer-of-memory-management-numa-placement.patch selftests-mm-khugepaged-remove-str_dup-usage.patch mm-sparse-move-mem_section-init-to-sparse_extreme_init.patch mm-sparse-refactor-sparse_sections_init.patch mm-sparse-move-initialization-of-section-metadata-to-sparse_metadata_init.patch mm-sparse-rename-and-cleanup-sparse_init_nid.patch mm-sparse-cleanup-sparse_init_one_section.patch mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr.patch mm-sparse-remove-pfn_in_present_section.patch mm-sparse-move-__highest_used_section_nr-handling.patch scripts-gdb-mmpy-remove-fallbacks-for-section_has_mem_map-and-section_is_early.patch mm-sparse-remove-section_marked_present.patch mm-sparse-remove-flags-parameter-from-sparse_init_one_section.patch fs-proc-page-clarify-comment-in-get_max_dump_pfn.patch mm-memory_hotplug-drop-config_have_arch_pfn_valid-handling-from-pfn_to_online_page.patch