tmpfs: convert mem_cgroup shmem to radix-swap
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 <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/shmem.c b/mm/shmem.c
index 92f01d7..13ef2d7 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -262,15 +262,11 @@
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 @@
}
if (error)
mem_cgroup_uncharge_cache_page(page);
-out:
return error;
}
@@ -660,7 +655,6 @@
* 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 @@
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 @@
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);
@@ -2442,42 +2442,6 @@
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 */
/*
@@ -2523,31 +2487,6 @@
}
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)