The patch titled Subject: mm/swap: optimise get_shadow_from_swap_cache has been added to the -mm tree. Its filename is mm-swap-optimise-get_shadow_from_swap_cache.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-swap-optimise-get_shadow_from_swap_cache.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-swap-optimise-get_shadow_from_swap_cache.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm/swap: optimise get_shadow_from_swap_cache There's no need to get a reference to the page, just load the entry and see if it's a shadow entry. Link: https://lkml.kernel.org/r/20201112212641.27837-4-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Dave Chinner <dchinner@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: William Kucharski <william.kucharski@xxxxxxxxxx> Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/swap_state.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/mm/swap_state.c~mm-swap-optimise-get_shadow_from_swap_cache +++ a/mm/swap_state.c @@ -113,11 +113,9 @@ void *get_shadow_from_swap_cache(swp_ent pgoff_t idx = swp_offset(entry); struct page *page; - page = find_get_entry(address_space, idx); + page = xa_load(&address_space->i_pages, idx); if (xa_is_value(page)) return page; - if (page) - put_page(page); return NULL; } _ Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are mm-fix-readahead_page_batch-for-retry-entries.patch mm-fix-madvise-willneed-performance-problem.patch mm-page-flags-fix-comment.patch mm-page_alloc-add-__free_pages-documentation.patch mm-make-pagecache-tagged-lookups-return-only-head-pages.patch mm-shmem-use-pagevec_lookup-in-shmem_unlock_mapping.patch mm-swap-optimise-get_shadow_from_swap_cache.patch mm-add-fgp_entry.patch mm-filemap-rename-find_get_entry-to-mapping_get_entry.patch mm-filemap-add-helper-for-finding-pages.patch mm-filemap-add-mapping_seek_hole_data.patch iomap-use-mapping_seek_hole_data.patch mm-add-and-use-find_lock_entries.patch mm-add-an-end-parameter-to-find_get_entries.patch mm-add-an-end-parameter-to-pagevec_lookup_entries.patch mm-remove-nr_entries-parameter-from-pagevec_lookup_entries.patch mm-pass-pvec-directly-to-find_get_entries.patch mm-remove-pagevec_lookup_entries.patch mm-truncateshmem-handle-truncates-that-split-thps.patch mm-filemap-return-only-head-pages-from-find_get_entries.patch mm-introduce-memfd_secret-system-call-to-create-secret-memory-areas-fix.patch