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.
Cc: Johannes Weiner <jweiner@xxxxxxxxxx>
Signed-off-by: Bob Liu <lliubbo@xxxxxxxxx>
---
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 aaa60da..1153095 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 8880a32..bc396e7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2405,7 +2405,7 @@ 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))
@@ -5114,7 +5114,7 @@ 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 53b5d43..b99d19e 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)
--
1.7.0.4
--
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