The patch titled tmpfs: shuffle add_to_swap_caches has been added to the -mm tree. Its filename is tmpfs-shuffle-add_to_swap_caches.patch *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: tmpfs: shuffle add_to_swap_caches From: Hugh Dickins <hugh@xxxxxxxxxxx> add_to_swap_cache doesn't amount to much: merge it into its sole caller read_swap_cache_async. But we'll be needing to call __add_to_swap_cache from shmem.c, so promote it to the new add_to_swap_cache. Both were static, so there's no interface confusion to worry about. And lose that inappropriate "Anon pages are already on the LRU" comment in the merging: they're not already on the LRU, as Nick Piggin noticed. Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/swap_state.c | 53 ++++++++++++++++------------------------------ 1 file changed, 19 insertions(+), 34 deletions(-) diff -puN mm/swap_state.c~tmpfs-shuffle-add_to_swap_caches mm/swap_state.c --- a/mm/swap_state.c~tmpfs-shuffle-add_to_swap_caches +++ a/mm/swap_state.c @@ -64,10 +64,10 @@ void show_swap_cache_info(void) } /* - * __add_to_swap_cache resembles add_to_page_cache on swapper_space, + * add_to_swap_cache resembles add_to_page_cache on swapper_space, * but sets SwapCache flag and private instead of mapping and index. */ -static int __add_to_swap_cache(struct page *page, swp_entry_t entry, +static int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask) { int error; @@ -94,28 +94,6 @@ static int __add_to_swap_cache(struct pa return error; } -static int add_to_swap_cache(struct page *page, swp_entry_t entry, - gfp_t gfp_mask) -{ - int error; - - BUG_ON(PageLocked(page)); - if (!swap_duplicate(entry)) - return -ENOENT; - - SetPageLocked(page); - error = __add_to_swap_cache(page, entry, gfp_mask & GFP_KERNEL); - /* - * Anon pages are already on the LRU, we don't run lru_cache_add here. - */ - if (error) { - ClearPageLocked(page); - swap_free(entry); - return error; - } - return 0; -} - /* * This must be called only on pages that have * been verified to be in the swap cache. @@ -165,7 +143,7 @@ int add_to_swap(struct page * page, gfp_ /* * Add it to the swap cache and mark it dirty */ - err = __add_to_swap_cache(page, entry, + err = add_to_swap_cache(page, entry, gfp_mask|__GFP_NOMEMALLOC|__GFP_NOWARN); switch (err) { @@ -210,7 +188,7 @@ void delete_from_swap_cache(struct page */ int move_to_swap_cache(struct page *page, swp_entry_t entry) { - int err = __add_to_swap_cache(page, entry, GFP_ATOMIC); + int err = add_to_swap_cache(page, entry, GFP_ATOMIC); if (!err) { remove_from_page_cache(page); page_cache_release(page); /* pagecache ref */ @@ -335,16 +313,21 @@ struct page *read_swap_cache_async(swp_e } /* + * Swap entry may have been freed since our caller observed it. + */ + if (!swap_duplicate(entry)) + break; + + /* * Associate the page with swap entry in the swap cache. - * May fail (-ENOENT) if swap entry has been freed since - * our caller observed it. May fail (-EEXIST) if there - * is already a page associated with this entry in the - * swap cache: added by a racing read_swap_cache_async, - * or by try_to_swap_out (or shmem_writepage) re-using - * the just freed swap entry for an existing page. + * May fail (-EEXIST) if there is already a page associated + * with this entry in the swap cache: added by a racing + * read_swap_cache_async, or add_to_swap or shmem_writepage + * re-using the just freed swap entry for an existing page. * May fail (-ENOMEM) if radix-tree node allocation failed. */ - err = add_to_swap_cache(new_page, entry, gfp_mask); + SetPageLocked(new_page); + err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL); if (!err) { /* * Initiate read into locked page and return. @@ -353,7 +336,9 @@ struct page *read_swap_cache_async(swp_e swap_readpage(NULL, new_page); return new_page; } - } while (err != -ENOENT && err != -ENOMEM); + ClearPageLocked(new_page); + swap_free(entry); + } while (err != -ENOMEM); if (new_page) page_cache_release(new_page); _ Patches currently in -mm which might be from hugh@xxxxxxxxxxx are git-unionfs.patch swapin_readahead-excise-numa-bogosity.patch swapin_readahead-move-and-rearrange-args.patch swapin-needs-gfp_mask-for-loop-on-tmpfs.patch shmem-sgp_quick-and-sgp_fault-redundant.patch shmem_getpage-return-page-locked.patch shmem_file_write-is-redundant.patch swapin-fix-valid_swaphandles-defect.patch swapoff-scan-ptes-preemptibly.patch shmem-factor-out-sbi-free_inodes-manipulations.patch shmem-factor-out-sbi-free_inodes-manipulations-fix.patch tmpfs-fix-mounts-when-size-is-less-than-the-page-size.patch tmpfs-move-swap_state-stats-update.patch tmpfs-shuffle-add_to_swap_caches.patch tmpfs-move-swap-swizzling-into-shmem.patch tmpfs-allow-filepage-alongside-swappage.patch tmpfs-allocate-on-read-when-stacked.patch tmpfs-make-shmem_unuse-more-preemptible.patch tmpfs-open-a-window-in-shmem_unuse_inode.patch tmpfs-radix_tree_preloading.patch tmpfs-fix-shmem_swaplist-races.patch maps4-add-proportional-set-size-accounting-in-smaps.patch mm-dont-waste-swap-on-locked-pages.patch skip-writing-data-pages-when-inode-is-under-i_sync.patch printk-trivial-optimizations-fix.patch r-o-bind-mounts-track-number-of-mount-writer-fix-buggy-loop.patch r-o-bind-mounts-track-number-of-mount-writer-fix-buggy-loop-checkpatch-fixes.patch memcgroup-temporarily-revert-swapoff-mod.patch memory-controller-memory-accounting-v7.patch memory-controller-add-per-container-lru-and-reclaim-v7-memcgroup-fix-try_to_free-order.patch memcgroup-reinstate-swapoff-mod.patch memcgroup-fix-zone-isolation-oom.patch memcgroup-revert-swap_state-mods.patch prio_tree-debugging-patch.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html