Now that mem_cgroup_swapout() fully uncharges the page, every page
that is still in use when reaching mem_cgroup_uncharge() is known to
carry both the memory and the memory+swap charge. Simplify the
uncharge path and remove the PCG_MEMSW page flag accordingly.
Signed-off-by: Johannes Weiner <han...@cmpxchg.org>
---
include/linux/page_cgroup.h | 1 -
mm/memcontrol.c | 34 ++++++++++++----------------------
2 files changed, 12 insertions(+), 23 deletions(-)
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 5c831f1eca79..da62ee2be28b 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -5,7 +5,6 @@ enum {
/* flags for mem_cgroup */
PCG_USED = 0x01, /* This page is charged to a memcg */
PCG_MEM = 0x02, /* This page holds a memory charge */
- PCG_MEMSW = 0x04, /* This page holds a memory+swap charge */
};
struct pglist_data;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7709f17347f3..9bab35fc3e9e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2606,7 +2606,7 @@ static void commit_charge(struct page *page, struct
mem_cgroup *memcg,
* have the page locked
*/
pc->mem_cgroup = memcg;
- pc->flags = PCG_USED | PCG_MEM | (do_swap_account ? PCG_MEMSW : 0);
+ pc->flags = PCG_USED | PCG_MEM;
if (lrucare)
unlock_page_lru(page, isolated);
@@ -5815,7 +5815,6 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t
entry)
if (!PageCgroupUsed(pc))
return;
- VM_BUG_ON_PAGE(!(pc->flags & PCG_MEMSW), page);
memcg = pc->mem_cgroup;
oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg));
@@ -6010,17 +6009,16 @@ void mem_cgroup_cancel_charge(struct page *page, struct
mem_cgroup *memcg)
}
static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
- unsigned long nr_mem, unsigned long nr_memsw,
unsigned long nr_anon, unsigned long nr_file,
unsigned long nr_huge, struct page *dummy_page)
{
+ unsigned long nr_pages = nr_anon + nr_file;
unsigned long flags;
if (!mem_cgroup_is_root(memcg)) {
- if (nr_mem)
- page_counter_uncharge(&memcg->memory, nr_mem);
- if (nr_memsw)
- page_counter_uncharge(&memcg->memsw, nr_memsw);
+ page_counter_uncharge(&memcg->memory, nr_pages);
+ if (do_swap_account)
+ page_counter_uncharge(&memcg->memsw, nr_pages);
memcg_oom_recover(memcg);
}
@@ -6029,23 +6027,21 @@ static void uncharge_batch(struct mem_cgroup *memcg,
unsigned long pgpgout,
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file);
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge);
__this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout);
- __this_cpu_add(memcg->stat->nr_page_events, nr_anon + nr_file);
+ __this_cpu_add(memcg->stat->nr_page_events, nr_pages);
memcg_check_events(memcg, dummy_page);
local_irq_restore(flags);
if (!mem_cgroup_is_root(memcg))
- css_put_many(&memcg->css, max(nr_mem, nr_memsw));
+ css_put_many(&memcg->css, nr_pages);
}
static void uncharge_list(struct list_head *page_list)
{
struct mem_cgroup *memcg = NULL;
- unsigned long nr_memsw = 0;
unsigned long nr_anon = 0;
unsigned long nr_file = 0;
unsigned long nr_huge = 0;
unsigned long pgpgout = 0;
- unsigned long nr_mem = 0;
struct list_head *next;
struct page *page;
@@ -6072,10 +6068,9 @@ static void uncharge_list(struct list_head *page_list)
if (memcg != pc->mem_cgroup) {
if (memcg) {
- uncharge_batch(memcg, pgpgout, nr_mem, nr_memsw,
- nr_anon, nr_file, nr_huge, page);
- pgpgout = nr_mem = nr_memsw = 0;
- nr_anon = nr_file = nr_huge = 0;
+ uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
+ nr_huge, page);
+ pgpgout = nr_anon = nr_file = nr_huge = 0;
}
memcg = pc->mem_cgroup;
}
@@ -6091,18 +6086,14 @@ static void uncharge_list(struct list_head *page_list)
else
nr_file += nr_pages;
- if (pc->flags & PCG_MEM)
- nr_mem += nr_pages;
- if (pc->flags & PCG_MEMSW)
- nr_memsw += nr_pages;
pc->flags = 0;
pgpgout++;
} while (next != page_list);
if (memcg)
- uncharge_batch(memcg, pgpgout, nr_mem, nr_memsw,
- nr_anon, nr_file, nr_huge, page);
+ uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
+ nr_huge, page);
}
/**
@@ -6187,7 +6178,6 @@ void mem_cgroup_migrate(struct page *oldpage, struct page
*newpage,
return;
VM_BUG_ON_PAGE(!(pc->flags & PCG_MEM), oldpage);
- VM_BUG_ON_PAGE(do_swap_account && !(pc->flags & PCG_MEMSW), oldpage);
if (lrucare)
lock_page_lru(oldpage, &isolated);
--
2.1.2
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