Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756151Ab1FNKzS (ORCPT ); Tue, 14 Jun 2011 06:55:18 -0400 Received: from smtp-out.google.com ([74.125.121.67]:11609 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756084Ab1FNKzO (ORCPT ); Tue, 14 Jun 2011 06:55:14 -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=obgqQbXT4QS7CmIZ+VnA2x5Y33x8IQw5lP2doLRJ2+5Zld9F72o6FKpUqTh3EfPLgw muahSnju4FrdH0+6fs/A== Date: Tue, 14 Jun 2011 03:54:59 -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 9/12] tmpfs: convert mem_cgroup shmem to 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: 9886 Lines: 298 Remove mem_cgroup_shmem_charge_fallback(): it was only required when we had to move swappage to filecache with GFP_NOWAIT. Remove the GFP_NOWAIT special case from mem_cgroup_cache_charge(), by moving its call out from shmem_add_to_page_cache() to two of thats three callers. But leave it doing mem_cgroup_uncharge_cache_page() on error: although asymmetrical, it's easier for all 3 callers to handle. These two changes would also be appropriate if anyone were to start using shmem_read_mapping_page_gfp() with GFP_NOWAIT. Remove mem_cgroup_get_shmem_target(): mc_handle_file_pte() can test radix_tree_exceptional_entry() to get what it needs for itself. Signed-off-by: Hugh Dickins --- include/linux/memcontrol.h | 8 --- include/linux/shmem_fs.h | 2 mm/memcontrol.c | 66 +++------------------------ mm/shmem.c | 83 ++++------------------------------- 4 files changed, 20 insertions(+), 139 deletions(-) --- linux.orig/include/linux/memcontrol.h 2011-06-13 13:26:07.126099155 -0700 +++ linux/include/linux/memcontrol.h 2011-06-13 13:30:05.951283422 -0700 @@ -76,8 +76,6 @@ extern void mem_cgroup_uncharge_end(void extern void mem_cgroup_uncharge_page(struct page *page); extern void mem_cgroup_uncharge_cache_page(struct page *page); -extern int mem_cgroup_shmem_charge_fallback(struct page *page, - struct mm_struct *mm, gfp_t gfp_mask); extern void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask); int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem); @@ -206,12 +204,6 @@ static inline void mem_cgroup_uncharge_c { } -static inline int mem_cgroup_shmem_charge_fallback(struct page *page, - struct mm_struct *mm, gfp_t gfp_mask) -{ - return 0; -} - static inline void mem_cgroup_add_lru_list(struct page *page, int lru) { } --- linux.orig/include/linux/shmem_fs.h 2011-06-13 13:28:25.822786909 -0700 +++ linux/include/linux/shmem_fs.h 2011-06-14 00:45:20.625161293 -0700 @@ -57,8 +57,6 @@ extern struct page *shmem_read_mapping_p pgoff_t index, gfp_t gfp_mask); extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); extern int shmem_unuse(swp_entry_t entry, struct page *page); -extern void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff, - struct page **pagep, swp_entry_t *ent); static inline struct page *shmem_read_mapping_page( struct address_space *mapping, pgoff_t index) --- linux.orig/mm/memcontrol.c 2011-06-13 13:26:07.446100738 -0700 +++ linux/mm/memcontrol.c 2011-06-14 00:50:17.346633542 -0700 @@ -35,7 +35,6 @@ #include #include #include -#include #include #include #include @@ -2690,30 +2689,6 @@ int mem_cgroup_cache_charge(struct page return 0; if (PageCompound(page)) return 0; - /* - * Corner case handling. This is called from add_to_page_cache() - * in usual. But some FS (shmem) precharges this page before calling it - * and call add_to_page_cache() with GFP_NOWAIT. - * - * For GFP_NOWAIT case, the page may be pre-charged before calling - * add_to_page_cache(). (See shmem.c) check it here and avoid to call - * charge twice. (It works but has to pay a bit larger cost.) - * And when the page is SwapCache, it should take swap information - * into account. This is under lock_page() now. - */ - if (!(gfp_mask & __GFP_WAIT)) { - struct page_cgroup *pc; - - pc = lookup_page_cgroup(page); - if (!pc) - return 0; - lock_page_cgroup(pc); - if (PageCgroupUsed(pc)) { - unlock_page_cgroup(pc); - return 0; - } - unlock_page_cgroup(pc); - } if (unlikely(!mm)) mm = &init_mm; @@ -3303,31 +3278,6 @@ void mem_cgroup_end_migration(struct mem cgroup_release_and_wakeup_rmdir(&mem->css); } -/* - * A call to try to shrink memory usage on charge failure at shmem's swapin. - * Calling hierarchical_reclaim is not enough because we should update - * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM. - * Moreover considering hierarchy, we should reclaim from the mem_over_limit, - * not from the memcg which this page would be charged to. - * try_charge_swapin does all of these works properly. - */ -int mem_cgroup_shmem_charge_fallback(struct page *page, - struct mm_struct *mm, - gfp_t gfp_mask) -{ - struct mem_cgroup *mem; - int ret; - - if (mem_cgroup_disabled()) - return 0; - - ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); - if (!ret) - mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */ - - return ret; -} - #ifdef CONFIG_DEBUG_VM static struct page_cgroup *lookup_page_cgroup_used(struct page *page) { @@ -5086,15 +5036,17 @@ static struct page *mc_handle_file_pte(s pgoff = pte_to_pgoff(ptent); /* page is moved even if it's not RSS of this task(page-faulted). */ - if (!mapping_cap_swap_backed(mapping)) { /* normal file */ - page = find_get_page(mapping, pgoff); - } else { /* shmem/tmpfs file. we should take account of swap too. */ - swp_entry_t ent; - mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent); + page = find_get_page(mapping, pgoff); + +#ifdef CONFIG_SWAP + /* shmem/tmpfs may report page out on swap: account for that too. */ + if (radix_tree_exceptional_entry(page)) { + swp_entry_t swap = radix_to_swp_entry(page); if (do_swap_account) - entry->val = ent.val; + *entry = swap; + page = find_get_page(&swapper_space, swap.val); } - +#endif return page; } --- linux.orig/mm/shmem.c 2011-06-13 13:29:55.115229689 -0700 +++ linux/mm/shmem.c 2011-06-14 00:45:20.685161581 -0700 @@ -262,15 +262,11 @@ static int shmem_add_to_page_cache(struc struct address_space *mapping, pgoff_t index, gfp_t gfp, void *expected) { - int error; + int error = 0; VM_BUG_ON(!PageLocked(page)); VM_BUG_ON(!PageSwapBacked(page)); - error = mem_cgroup_cache_charge(page, current->mm, - gfp & GFP_RECLAIM_MASK); - if (error) - goto out; if (!expected) error = radix_tree_preload(gfp & GFP_RECLAIM_MASK); if (!error) { @@ -300,7 +296,6 @@ static int shmem_add_to_page_cache(struc } if (error) mem_cgroup_uncharge_cache_page(page); -out: return error; } @@ -660,7 +655,6 @@ int shmem_unuse(swp_entry_t swap, struct * Charge page using GFP_KERNEL while we can wait, before taking * the shmem_swaplist_mutex which might hold up shmem_writepage(). * Charged back to the user (not to caller) when swap account is used. - * shmem_add_to_page_cache() will be called with GFP_NOWAIT. */ error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL); if (error) @@ -954,8 +948,11 @@ repeat: goto failed; } - error = shmem_add_to_page_cache(page, mapping, index, - gfp, swp_to_radix_entry(swap)); + error = mem_cgroup_cache_charge(page, current->mm, + gfp & GFP_RECLAIM_MASK); + if (!error) + error = shmem_add_to_page_cache(page, mapping, index, + gfp, swp_to_radix_entry(swap)); if (error) goto failed; @@ -990,8 +987,11 @@ repeat: SetPageSwapBacked(page); __set_page_locked(page); - error = shmem_add_to_page_cache(page, mapping, index, - gfp, NULL); + error = mem_cgroup_cache_charge(page, current->mm, + gfp & GFP_RECLAIM_MASK); + if (!error) + error = shmem_add_to_page_cache(page, mapping, index, + gfp, NULL); if (error) goto decused; lru_cache_add_anon(page); @@ -2448,42 +2448,6 @@ out4: return error; } -#ifdef CONFIG_CGROUP_MEM_RES_CTLR -/** - * mem_cgroup_get_shmem_target - find page or swap assigned to the shmem file - * @inode: the inode to be searched - * @index: the page offset to be searched - * @pagep: the pointer for the found page to be stored - * @swapp: the pointer for the found swap entry to be stored - * - * If a page is found, refcount of it is incremented. Callers should handle - * these refcount. - */ -void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t index, - struct page **pagep, swp_entry_t *swapp) -{ - struct shmem_inode_info *info = SHMEM_I(inode); - struct page *page = NULL; - swp_entry_t swap = {0}; - - if ((index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) - goto out; - - spin_lock(&info->lock); -#ifdef CONFIG_SWAP - swap = shmem_get_swap(info, index); - if (swap.val) - page = find_get_page(&swapper_space, swap.val); - else -#endif - page = find_get_page(inode->i_mapping, index); - spin_unlock(&info->lock); -out: - *pagep = page; - *swapp = swap; -} -#endif - #else /* !CONFIG_SHMEM */ /* @@ -2529,31 +2493,6 @@ void shmem_truncate_range(struct inode * } EXPORT_SYMBOL_GPL(shmem_truncate_range); -#ifdef CONFIG_CGROUP_MEM_RES_CTLR -/** - * mem_cgroup_get_shmem_target - find page or swap assigned to the shmem file - * @inode: the inode to be searched - * @index: the page offset to be searched - * @pagep: the pointer for the found page to be stored - * @swapp: the pointer for the found swap entry to be stored - * - * If a page is found, refcount of it is incremented. Callers should handle - * these refcount. - */ -void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t index, - struct page **pagep, swp_entry_t *swapp) -{ - struct page *page = NULL; - - if ((index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) - goto out; - page = find_get_page(inode->i_mapping, index); -out: - *pagep = page; - *swapp = (swp_entry_t){0}; -} -#endif - #define shmem_vm_ops generic_file_vm_ops #define shmem_file_operations ramfs_file_operations #define shmem_get_inode(sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev) -- 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/