From b065b4321fa78e83bf8f5b0d79d0b5424b57998b Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Wed, 11 Jul 2012 14:02:48 -0700 Subject: [PATCH] shmem: cleanup shmem_add_to_page_cache shmem_add_to_page_cache() has three callsites, but only one of them wants the radix_tree_preload() (an exceptional entry guarantees that the radix tree node is present in the other cases), and only that site can achieve mem_cgroup_uncharge_cache_page() (PageSwapCache makes it a no-op in the other cases). We did it this way originally to reflect add_to_page_cache_locked(); but it's confusing now, so move the radix_tree preloading and mem_cgroup uncharging to that one caller. Signed-off-by: Hugh Dickins Acked-by: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 58 ++++++++++++++++++++++++++---------------------------- 1 file changed, 28 insertions(+), 30 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 294364a24a1f..bd106361be4b 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -288,40 +288,31 @@ static int shmem_add_to_page_cache(struct page *page, struct address_space *mapping, pgoff_t index, gfp_t gfp, void *expected) { - int error = 0; + int error; VM_BUG_ON(!PageLocked(page)); VM_BUG_ON(!PageSwapBacked(page)); + page_cache_get(page); + page->mapping = mapping; + page->index = index; + + spin_lock_irq(&mapping->tree_lock); if (!expected) - error = radix_tree_preload(gfp & GFP_RECLAIM_MASK); + error = radix_tree_insert(&mapping->page_tree, index, page); + else + error = shmem_radix_tree_replace(mapping, index, expected, + page); if (!error) { - page_cache_get(page); - page->mapping = mapping; - page->index = index; - - spin_lock_irq(&mapping->tree_lock); - if (!expected) - error = radix_tree_insert(&mapping->page_tree, - index, page); - else - error = shmem_radix_tree_replace(mapping, index, - expected, page); - if (!error) { - mapping->nrpages++; - __inc_zone_page_state(page, NR_FILE_PAGES); - __inc_zone_page_state(page, NR_SHMEM); - spin_unlock_irq(&mapping->tree_lock); - } else { - page->mapping = NULL; - spin_unlock_irq(&mapping->tree_lock); - page_cache_release(page); - } - if (!expected) - radix_tree_preload_end(); + mapping->nrpages++; + __inc_zone_page_state(page, NR_FILE_PAGES); + __inc_zone_page_state(page, NR_SHMEM); + spin_unlock_irq(&mapping->tree_lock); + } else { + page->mapping = NULL; + spin_unlock_irq(&mapping->tree_lock); + page_cache_release(page); } - if (error) - mem_cgroup_uncharge_cache_page(page); return error; } @@ -1202,11 +1193,18 @@ repeat: __set_page_locked(page); 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; + error = radix_tree_preload(gfp & GFP_RECLAIM_MASK); + if (!error) { + error = shmem_add_to_page_cache(page, mapping, index, + gfp, NULL); + radix_tree_preload_end(); + } + if (error) { + mem_cgroup_uncharge_cache_page(page); + goto decused; + } lru_cache_add_anon(page); spin_lock(&info->lock); -- 2.20.1