From d876f2c9d3f6281f04795634bed75195cb18c745 Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Fri, 16 Dec 2011 15:50:38 +1100 Subject: [PATCH] page_cgroup: cleanup lookup_swap_cgroup() This patch is based on my previous patch: page_cgroup: add helper function to get swap_cgroup As Johannes suggested, change the public interface to lookup_swap_cgroup_id(), replace swap_cgroup_getsc() with lookup_swap_cgroup() and do some extra cleanup. Signed-off-by: Bob Liu Acked-by: Johannes Weiner Cc: Michal Hocko Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton --- include/linux/page_cgroup.h | 4 ++-- mm/memcontrol.c | 4 ++-- mm/page_cgroup.c | 35 ++++++++++++++--------------------- 3 files changed, 18 insertions(+), 25 deletions(-) diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h index aaa60da8783c..1153095ee457 100644 --- a/include/linux/page_cgroup.h +++ b/include/linux/page_cgroup.h @@ -149,7 +149,7 @@ static inline void __init page_cgroup_init_flatmem(void) extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, unsigned short old, unsigned short new); extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id); -extern unsigned short lookup_swap_cgroup(swp_entry_t ent); +extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent); extern int swap_cgroup_swapon(int type, unsigned long max_pages); extern void swap_cgroup_swapoff(int type); #else @@ -161,7 +161,7 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) } static inline -unsigned short lookup_swap_cgroup(swp_entry_t ent) +unsigned short lookup_swap_cgroup_id(swp_entry_t ent) { return 0; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b2ae95160b32..a2fcb58e20a6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2476,7 +2476,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) memcg = NULL; } else if (PageSwapCache(page)) { ent.val = page_private(page); - id = lookup_swap_cgroup(ent); + id = lookup_swap_cgroup_id(ent); rcu_read_lock(); memcg = mem_cgroup_lookup(id); if (memcg && !css_tryget(&memcg->css)) @@ -5332,7 +5332,7 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma, } /* There is a swap entry and a page doesn't exist or isn't charged */ if (ent.val && !ret && - css_id(&mc.from->css) == lookup_swap_cgroup(ent)) { + css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { ret = MC_TARGET_SWAP; if (target) target->ent = ent; diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c index 53b5d43c1546..b99d19edf89b 100644 --- a/mm/page_cgroup.c +++ b/mm/page_cgroup.c @@ -334,7 +334,6 @@ struct swap_cgroup { unsigned short id; }; #define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup)) -#define SC_POS_MASK (SC_PER_PAGE - 1) /* * SwapCgroup implements "lookup" and "exchange" operations. @@ -376,25 +375,19 @@ not_enough_page: return -ENOMEM; } -static struct swap_cgroup *swap_cgroup_getsc(swp_entry_t ent, - struct swap_cgroup_ctrl **ctrl) +static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent, + struct swap_cgroup_ctrl **ctrlp) { - int type = swp_type(ent); - unsigned long offset = swp_offset(ent); - unsigned long idx = offset / SC_PER_PAGE; - unsigned long pos = offset & SC_POS_MASK; - struct swap_cgroup_ctrl *temp_ctrl; + pgoff_t offset = swp_offset(ent); + struct swap_cgroup_ctrl *ctrl; struct page *mappage; - struct swap_cgroup *sc; - temp_ctrl = &swap_cgroup_ctrl[type]; - if (ctrl) - *ctrl = temp_ctrl; + ctrl = &swap_cgroup_ctrl[swp_type(ent)]; + if (ctrlp) + *ctrlp = ctrl; - mappage = temp_ctrl->map[idx]; - sc = page_address(mappage); - sc += pos; - return sc; + mappage = ctrl->map[offset / SC_PER_PAGE]; + return page_address(mappage) + offset % SC_PER_PAGE; } /** @@ -414,7 +407,7 @@ unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, unsigned long flags; unsigned short retval; - sc = swap_cgroup_getsc(ent, &ctrl); + sc = lookup_swap_cgroup(ent, &ctrl); spin_lock_irqsave(&ctrl->lock, flags); retval = sc->id; @@ -441,7 +434,7 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) unsigned short old; unsigned long flags; - sc = swap_cgroup_getsc(ent, &ctrl); + sc = lookup_swap_cgroup(ent, &ctrl); spin_lock_irqsave(&ctrl->lock, flags); old = sc->id; @@ -452,14 +445,14 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) } /** - * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry + * lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry * @ent: swap entry to be looked up. * * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID) */ -unsigned short lookup_swap_cgroup(swp_entry_t ent) +unsigned short lookup_swap_cgroup_id(swp_entry_t ent) { - return swap_cgroup_getsc(ent, NULL)->id; + return lookup_swap_cgroup(ent, NULL)->id; } int swap_cgroup_swapon(int type, unsigned long max_pages) -- 2.39.5