The patch titled Subject: hugetlb: add comment for subtle SetHPageVmemmapOptimized() has been added to the -mm mm-unstable branch. Its filename is hugetlb-add-comment-for-subtle-sethpagevmemmapoptimized.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hugetlb-add-comment-for-subtle-sethpagevmemmapoptimized.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: hugetlb: add comment for subtle SetHPageVmemmapOptimized() Date: Thu, 1 Sep 2022 20:00:28 +0800 The SetHPageVmemmapOptimized() called here seems unnecessary as it's assumed to be set when calling this function. But it's indeed cleared by above set_page_private(page, 0). Add a comment to avoid possible future confusion. Link: https://lkml.kernel.org/r/20220901120030.63318-9-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/mm/hugetlb.c~hugetlb-add-comment-for-subtle-sethpagevmemmapoptimized +++ a/mm/hugetlb.c @@ -1520,6 +1520,10 @@ static void add_hugetlb_page(struct hsta set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); set_page_private(page, 0); + /* + * We have to set HPageVmemmapOptimized again as above + * set_page_private(page, 0) cleared it. + */ SetHPageVmemmapOptimized(page); /* _ Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are mm-page_alloc-minor-clean-up-for-memmap_init_compound.patch hugetlb_cgroup-remove-unneeded-nr_pages-0-check.patch hugetlb_cgroup-hugetlbfs-use-helper-macro-sz_1kmg.patch hugetlb_cgroup-remove-unneeded-return-value.patch hugetlb_cgroup-use-helper-macro-numa_no_node.patch hugetlb_cgroup-use-helper-for_each_hstate-and-hstate_index.patch mm-hugetlb-fix-incorrect-update-of-max_huge_pages.patch mm-hugetlb-fix-warn_onkobj-in-sysfs_create_group.patch mm-hugetlb-fix-missing-call-to-restore_reserve_on_error.patch mm-hugetlb-fix-missing-call-to-restore_reserve_on_error-v2.patch mm-hugetlb_vmemmap-add-missing-smp_wmb-before-set_pte_at.patch mm-hugetlb-fix-sysfs-group-leak-in-hugetlb_unregister_node.patch mm-hugetlb-make-detecting-shared-pte-more-reliable.patch mm-hwpoison-fix-page-refcnt-leaking-in-try_memory_failure_hugetlb.patch mm-hwpoison-fix-page-refcnt-leaking-in-unpoison_memory.patch mm-hwpoison-fix-extra-put_page-in-soft_offline_page.patch mm-hwpoison-fix-possible-use-after-free-in-mf_dax_kill_procs-v2.patch mm-hwpoison-kill-procs-if-unmap-fails.patch mm-hwpoison-kill-procs-if-unmap-fails-v2.patch mm-hwpoison-avoid-trying-to-unpoison-reserved-page.patch mm-hwpoison-use-clearpagehwpoison-in-memory_failure.patch mm-hwpoison-use-__pagemovable-to-detect-non-lru-movable-pages.patch mm-hwpoison-use-num_poisoned_pages_sub-to-decrease-num_poisoned_pages.patch mm-hwpoison-avoid-unneeded-page_mapped_in_vma-overhead-in-collect_procs_anon.patch mm-hwpoison-check-pagetable-explicitly-in-hwpoison_user_mappings.patch mm-hwpoison-cleanup-some-obsolete-comments.patch hugetlb-make-hugetlb_cma_check-static.patch hugetlb-use-helper-macro-sz_1k.patch hugetlb-use-list_head-to-define-a-list-head.patch hugetlb-use-sizeof-to-get-the-array-size.patch hugetlb-use-helper-huge_ptepmd_lock.patch hugetlb-pass-null-to-kobj_to_hstate-if-nid-is-unused.patch hugetlb-kill-hugetlbfs_pagecache_page.patch hugetlb-add-comment-for-subtle-sethpagevmemmapoptimized.patch hugetlb-remove-meaningless-bug_onhuge_pte_none.patch hugetlb-make-hugetlb-depends-on-sysfs-or-sysctl.patch