Not all uncharge paths need to check if the page is swapcache, some of
them can know for sure.
Push down the check into all callsites of uncharge_common() so that
the patch that removes some of them is more obvious.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
mm/memcontrol.c | 18 ++++++++++++------
1 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4ea19c6..a3bf414 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2920,8 +2920,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
if (mem_cgroup_disabled())
return NULL;
- if (PageSwapCache(page))
- return NULL;
+ VM_BUG_ON(PageSwapCache(page));
if (PageTransHuge(page)) {
nr_pages <<= compound_order(page);
@@ -3018,6 +3017,8 @@ void mem_cgroup_uncharge_page(struct page *page)
if (page_mapped(page))
return;
VM_BUG_ON(page->mapping && !PageAnon(page));
+ if (PageSwapCache(page))
+ return;
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false);
}
@@ -3025,6 +3026,8 @@ void mem_cgroup_uncharge_cache_page(struct page *page)
{
VM_BUG_ON(page_mapped(page));
VM_BUG_ON(page->mapping);
+ if (PageSwapCache(page))
+ return;
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false);
}
@@ -3089,6 +3092,8 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
if (!swapout) /* this was a swap cache but the swap is unused ! */
ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
+ if (PageSwapCache(page))
+ return;
memcg = __mem_cgroup_uncharge_common(page, ctype, false);
/*
@@ -3278,10 +3283,11 @@ void mem_cgroup_end_migration(struct mem_cgroup *memcg,
unused = oldpage;
}
anon = PageAnon(used);
- __mem_cgroup_uncharge_common(unused,
- anon ? MEM_CGROUP_CHARGE_TYPE_ANON
- : MEM_CGROUP_CHARGE_TYPE_CACHE,
- true);
+ if (!PageSwapCache(page))
+ __mem_cgroup_uncharge_common(unused,
+ anon ? MEM_CGROUP_CHARGE_TYPE_ANON
+ : MEM_CGROUP_CHARGE_TYPE_CACHE,
+ true);
css_put(&memcg->css);
/*
* We disallowed uncharge of pages under migration because mapcount
--
1.7.7.6
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