+ ksm-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch added to -mm tree

+ ksm-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch added to -mm tree

[akpm]

The patch titled
     Subject: ksm: use GET_KSM_PAGE_NOLOCK to get ksm page in remove_rmap_item_from_tree()
has been added to the -mm tree.  Its filename is
     ksm-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/ksm-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/ksm-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: ksm: use GET_KSM_PAGE_NOLOCK to get ksm page in remove_rmap_item_from_tree()

It's unnecessary to lock the page when get ksm page if we're going to
remove the rmap item as page migration is irrelevant in this case.  Use
GET_KSM_PAGE_NOLOCK instead to save some page lock cycles.

Link: https://lkml.kernel.org/r/20210330140228.45635-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/ksm.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/mm/ksm.c~ksm-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree
+++ a/mm/ksm.c
@@ -778,12 +778,11 @@ static void remove_rmap_item_from_tree(s
 		struct page *page;
 
 		stable_node = rmap_item->head;
-		page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK);
+		page = get_ksm_page(stable_node, GET_KSM_PAGE_NOLOCK);
 		if (!page)
 			goto out;
 
 		hlist_del(&rmap_item->hlist);
-		unlock_page(page);
 		put_page(page);
 
 		if (!hlist_empty(&stable_node->hlist))
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-hugetlb-remove-redundant-reservation-check-condition-in-alloc_huge_page.patch
mm-hugetlb-use-some-helper-functions-to-cleanup-code.patch
mm-hugetlb-optimize-the-surplus-state-transfer-code-in-move_hugetlb_state.patch
hugetlb_cgroup-remove-unnecessary-vm_bug_on_page-in-hugetlb_cgroup_migrate.patch
mm-hugetlb-simplify-the-code-when-alloc_huge_page-failed-in-hugetlb_no_page.patch
mm-hugetlb-avoid-calculating-fault_mutex_hash-in-truncate_op-case.patch
khugepaged-remove-unneeded-return-value-of-khugepaged_collapse_pte_mapped_thps.patch
khugepaged-reuse-the-smp_wmb-inside-__setpageuptodate.patch
khugepaged-use-helper-khugepaged_test_exit-in-__khugepaged_enter.patch
khugepaged-fix-wrong-result-value-for-trace_mm_collapse_huge_page_isolate.patch
mm-huge_memoryc-remove-unnecessary-local-variable-ret2.patch
mm-huge_memoryc-rework-the-function-vma_adjust_trans_huge.patch
mm-huge_memoryc-make-get_huge_zero_page-return-bool.patch
mm-huge_memoryc-rework-the-function-do_huge_pmd_numa_page-slightly.patch
mm-huge_memoryc-remove-redundant-pagecompound-check.patch
mm-huge_memoryc-remove-unused-macro-transparent_hugepage_debug_cow_flag.patch
mm-huge_memoryc-use-helper-function-migration_entry_to_page.patch
khugepaged-use-helper-function-range_in_vma-in-collapse_pte_mapped_thp.patch
khugepaged-remove-unnecessary-out-label-in-collapse_huge_page.patch
khugepaged-remove-meaningless-pte_present-check-in-khugepaged_scan_pmd.patch
mm-migratec-make-putback_movable_page-static.patch
mm-migratec-remove-unnecessary-rc-=-migratepage_success-check-in-else-case.patch
mm-migratec-fix-potential-indeterminate-pte-entry-in-migrate_vma_insert_page.patch
mm-migratec-use-helper-migrate_vma_collect_skip-in-migrate_vma_collect_hole.patch
revert-mm-migrate-skip-shared-exec-thp-for-numa-balancing.patch
ksm-remove-redundant-vm_bug_on_page-on-stable_tree_search.patch
ksm-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch
ksm-remove-dedicated-macro-ksm_flag_mask.patch
ksm-fix-potential-missing-rmap_item-for-stable_node.patch