Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754344Ab1FOAtj (ORCPT ); Tue, 14 Jun 2011 20:49:39 -0400 Received: from smtp-out.google.com ([216.239.44.51]:3468 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751369Ab1FOAtg (ORCPT ); Tue, 14 Jun 2011 20:49:36 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version:content-type; b=oIHhDC8q9TJGXlj1CR4QqtKtBjOK4Lvau9qlUZj2U7dAOfnEWpdg5naSVNnIxRE4Rz 2VB3khM1pNHzx16ooPjw== Date: Tue, 14 Jun 2011 17:49:13 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@sister.anvils To: Andrew Morton cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 12/12] mm: a few small updates for radix-swap In-Reply-To: Message-ID: References: User-Agent: Alpine 2.00 (LSU 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5005 Lines: 130 Remove PageSwapBacked (!page_is_file_cache) cases from add_to_page_cache_locked() and add_to_page_cache_lru(): those pages now go through shmem_add_to_page_cache(). Remove a comment on maximum tmpfs size from fsstack_copy_inode_size(), and add a comment on swap entries to invalidate_mapping_pages(). And mincore_page() uses find_get_page() on what might be shmem or a tmpfs file: allow for a radix_tree_exceptional_entry(), and proceed to find_get_page() on swapper_space if so (oh, swapper_space needs #ifdef). v2: Fix NULL dereference I introduced in mincore_page(). Signed-off-by: Hugh Dickins --- fs/stack.c | 5 +---- mm/filemap.c | 21 +++------------------ mm/mincore.c | 10 ++++++---- mm/truncate.c | 8 ++++++++ 4 files changed, 18 insertions(+), 26 deletions(-) --- linux.orig/fs/stack.c 2011-06-14 01:22:10.768120780 -0700 +++ linux/fs/stack.c 2011-06-14 01:23:26.088494288 -0700 @@ -29,10 +29,7 @@ void fsstack_copy_inode_size(struct inod * * We don't actually know what locking is used at the lower level; * but if it's a filesystem that supports quotas, it will be using - * i_lock as in inode_add_bytes(). tmpfs uses other locking, and - * its 32-bit is (just) able to exceed 2TB i_size with the aid of - * holes; but its i_blocks cannot carry into the upper long without - * almost 2TB swap - let's ignore that case. + * i_lock as in inode_add_bytes(). */ if (sizeof(i_blocks) > sizeof(long)) spin_lock(&src->i_lock); --- linux.orig/mm/filemap.c 2011-06-14 01:22:10.768120780 -0700 +++ linux/mm/filemap.c 2011-06-14 01:23:26.088494288 -0700 @@ -33,7 +33,6 @@ #include #include /* for BUG_ON(!in_atomic()) only */ #include -#include /* for page_is_file_cache() */ #include #include "internal.h" @@ -465,6 +464,7 @@ int add_to_page_cache_locked(struct page int error; VM_BUG_ON(!PageLocked(page)); + VM_BUG_ON(PageSwapBacked(page)); error = mem_cgroup_cache_charge(page, current->mm, gfp_mask & GFP_RECLAIM_MASK); @@ -482,8 +482,6 @@ int add_to_page_cache_locked(struct page if (likely(!error)) { mapping->nrpages++; __inc_zone_page_state(page, NR_FILE_PAGES); - if (PageSwapBacked(page)) - __inc_zone_page_state(page, NR_SHMEM); spin_unlock_irq(&mapping->tree_lock); } else { page->mapping = NULL; @@ -505,22 +503,9 @@ int add_to_page_cache_lru(struct page *p { int ret; - /* - * Splice_read and readahead add shmem/tmpfs pages into the page cache - * before shmem_readpage has a chance to mark them as SwapBacked: they - * need to go on the anon lru below, and mem_cgroup_cache_charge - * (called in add_to_page_cache) needs to know where they're going too. - */ - if (mapping_cap_swap_backed(mapping)) - SetPageSwapBacked(page); - ret = add_to_page_cache(page, mapping, offset, gfp_mask); - if (ret == 0) { - if (page_is_file_cache(page)) - lru_cache_add_file(page); - else - lru_cache_add_anon(page); - } + if (ret == 0) + lru_cache_add_file(page); return ret; } EXPORT_SYMBOL_GPL(add_to_page_cache_lru); --- linux.orig/mm/mincore.c 2011-06-14 01:22:10.768120780 -0700 +++ linux/mm/mincore.c 2011-06-14 17:41:15.760211585 -0700 @@ -69,12 +69,14 @@ static unsigned char mincore_page(struct * file will not get a swp_entry_t in its pte, but rather it is like * any other file mapping (ie. marked !present and faulted in with * tmpfs's .fault). So swapped out tmpfs mappings are tested here. - * - * However when tmpfs moves the page from pagecache and into swapcache, - * it is still in core, but the find_get_page below won't find it. - * No big deal, but make a note of it. */ page = find_get_page(mapping, pgoff); +#ifdef CONFIG_SWAP + if (radix_tree_exceptional_entry(page)) { + swp_entry_t swap = radix_to_swp_entry(page); + page = find_get_page(&swapper_space, swap.val); + } +#endif if (page) { present = PageUptodate(page); page_cache_release(page); --- linux.orig/mm/truncate.c 2011-06-14 01:22:10.768120780 -0700 +++ linux/mm/truncate.c 2011-06-14 01:23:26.092494303 -0700 @@ -331,6 +331,14 @@ unsigned long invalidate_mapping_pages(s unsigned long count = 0; int i; + /* + * Note: this function may get called on a shmem/tmpfs mapping: + * pagevec_lookup() might then return 0 prematurely (because it + * got a gangful of swap entries); but it's hardly worth worrying + * about - it can rarely have anything to free from such a mapping + * (most pages are dirty), and already skips over any difficulties. + */ + pagevec_init(&pvec, 0); while (index <= end && pagevec_lookup(&pvec, mapping, index, min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/