+ mm-hugetlb-convert-hugetlbfs_pagecache_present-to-folios.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/hugetlb: convert hugetlbfs_pagecache_present() to folios
has been added to the -mm mm-unstable branch.  Its filename is
     mm-hugetlb-convert-hugetlbfs_pagecache_present-to-folios.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-convert-hugetlbfs_pagecache_present-to-folios.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Subject: mm/hugetlb: convert hugetlbfs_pagecache_present() to folios
Date: Wed, 25 Jan 2023 09:05:31 -0800

Refactor hugetlbfs_pagecache_present() to avoid getting and dropping a
refcount on a page.  Use RCU and page_cache_next_miss() instead.

Link: https://lkml.kernel.org/r/20230125170537.96973-3-sidhartha.kumar@oracle.com
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/hugetlb.c~mm-hugetlb-convert-hugetlbfs_pagecache_present-to-folios
+++ a/mm/hugetlb.c
@@ -5651,17 +5651,15 @@ out_release_old:
 static bool hugetlbfs_pagecache_present(struct hstate *h,
 			struct vm_area_struct *vma, unsigned long address)
 {
-	struct address_space *mapping;
-	pgoff_t idx;
-	struct page *page;
+	struct address_space *mapping = vma->vm_file->f_mapping;
+	pgoff_t idx = vma_hugecache_offset(h, vma, address);
+	bool present;
 
-	mapping = vma->vm_file->f_mapping;
-	idx = vma_hugecache_offset(h, vma, address);
+	rcu_read_lock();
+	present = page_cache_next_miss(mapping, idx, 1) != idx;
+	rcu_read_unlock();
 
-	page = find_get_page(mapping, idx);
-	if (page)
-		put_page(page);
-	return page != NULL;
+	return present;
 }
 
 int hugetlb_add_to_page_cache(struct page *page, struct address_space *mapping,
_

Patches currently in -mm which might be from sidhartha.kumar@oracle.com are

mm-remove-the-hugetlb-field-from-struct-page.patch
mm-memory-failure-convert-__get_huge_page_for_hwpoison-to-folios.patch
mm-memory-failure-convert-try_memory_failure_hugetlb-to-folios.patch
mm-memory-failure-convert-hugetlb_clear_page_hwpoison-to-folios.patch
mm-memory-failure-convert-free_raw_hwp_pages-to-folios.patch
mm-memory-failure-convert-raw_hwp_list_head-to-folios.patch
mm-memory-failure-convert-__free_raw_hwp_pages-to-folios.patch
mm-memory-failure-convert-hugetlb_set_page_hwpoison-to-folios.patch
mm-memory-failure-convert-unpoison_memory-to-folios.patch
mm-hugetlb-convert-isolate_hugetlb-to-folios.patch
mm-hugetlb-convert-__update_and_free_page-to-folios.patch
mm-hugetlb-convert-dequeue_hugetlb_page-functions-to-folios.patch
mm-hugetlb-convert-alloc_surplus_huge_page-to-folios.patch
mm-hugetlb-increase-use-of-folios-in-alloc_huge_page.patch
mm-hugetlb-convert-alloc_migrate_huge_page-to-folios.patch
mm-hugetlb-convert-restore_reserve_on_error-to-folios.patch
mm-hugetlb-convert-demote_free_huge_page-to-folios.patch
mm-hugetlb-convert-get_hwpoison_huge_page-to-folios.patch
mm-hugetlb-convert-hugetlb_install_page-to-folios.patch
mm-hugetlb-convert-hugetlbfs_pagecache_present-to-folios.patch
mm-hugetlb-convert-putback_active_hugepage-to-take-in-a-folio.patch
mm-hugetlb-convert-hugetlb-fault-paths-to-use-alloc_hugetlb_folio.patch
mm-hugetlb-convert-restore_reserve_on_error-to-take-in-a-folio.patch
mm-hugetlb-convert-hugetlb_add_to_page_cache-to-take-in-a-folio.patch
mm-hugetlb-convert-hugetlb_wp-to-take-in-a-folio.patch
documentation-mm-update-hugetlbfs-documentation-to-mention-alloc_hugetlb_folio.patch