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| author |   Matthew Wilcox <willy@infradead.org> | 2019-05-13 17:16:44 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-14 09:47:45 -0700 |
| commit | 5fd4ca2d84b249f0858ce28cf637cf25b61a398f (patch) | |
| tree | a7660b8f5f9fa02945070e2ab918eb645c92ba36 /include | |
| parent | userfaultfd/sysctl: add vm.unprivileged_userfaultfd (diff) | |
| download | linux-dev-5fd4ca2d84b249f0858ce28cf637cf25b61a398f.tar.xz linux-dev-5fd4ca2d84b249f0858ce28cf637cf25b61a398f.zip | |
mm: page cache: store only head pages in i_pages
Transparent Huge Pages are currently stored in i_pages as pointers to
consecutive subpages. This patch changes that to storing consecutive
pointers to the head page in preparation for storing huge pages more
efficiently in i_pages.
Large parts of this are "inspired" by Kirill's patch
https://lore.kernel.org/lkml/20170126115819.58875-2-kirill.shutemov@linux.intel.com/
[willy@infradead.org: fix swapcache pages]
Link: http://lkml.kernel.org/r/20190324155441.GF10344@bombadil.infradead.org
[kirill@shutemov.name: hugetlb stores pages in page cache differently]
Link: http://lkml.kernel.org/r/20190404134553.vuvhgmghlkiw2hgl@kshutemo-mobl1
Link: http://lkml.kernel.org/r/20190307153051.18815-1-willy@infradead.org
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Jan Kara <jack@suse.cz>
Reviewed-by: Kirill Shutemov <kirill@shutemov.name>
Reviewed-and-tested-by: Song Liu <songliubraving@fb.com>
Tested-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Hugh Dickins <hughd@google.com>
Cc: Song Liu <liu.song.a23@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pagemap.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index bcf909d0de5f..2e8438a1216a 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -333,6 +333,19 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping, mapping_gfp_mask(mapping)); } +static inline struct page *find_subpage(struct page *page, pgoff_t offset) +{ + unsigned long mask; + + if (PageHuge(page)) + return page; + + VM_BUG_ON_PAGE(PageTail(page), page); + + mask = (1UL << compound_order(page)) - 1; + return page + (offset & mask); +} + struct page *find_get_entry(struct address_space *mapping, pgoff_t offset); struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset); unsigned find_get_entries(struct address_space *mapping, pgoff_t start, |