The patch titled
Subject: mm: memcontrol: remove unnecessary PCG_MEMSW memory+swap charge flag
has been added to the -mm tree. Its filename is
mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm: memcontrol: remove unnecessary PCG_MEMSW memory+swap charge flag
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 <hannes@xxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/page_cgroup.h | 1 -
mm/memcontrol.c | 34 ++++++++++++----------------------
2 files changed, 12 insertions(+), 23 deletions(-)
diff -puN include/linux/page_cgroup.h~mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag include/linux/page_cgroup.h
--- a/include/linux/page_cgroup.h~mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag
+++ a/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 -puN mm/memcontrol.c~mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag mm/memcontrol.c
--- a/mm/memcontrol.c~mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag
+++ a/mm/memcontrol.c
@@ -2606,7 +2606,7 @@ static void commit_charge(struct page *p
* 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);
@@ -5785,7 +5785,6 @@ void mem_cgroup_swapout(struct page *pag
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));
@@ -5980,17 +5979,16 @@ void mem_cgroup_cancel_charge(struct pag
}
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);
}
@@ -5999,23 +5997,21 @@ static void uncharge_batch(struct mem_cg
__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;
@@ -6042,10 +6038,9 @@ static void uncharge_list(struct list_he
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;
}
@@ -6061,18 +6056,14 @@ static void uncharge_list(struct list_he
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);
}
/**
@@ -6157,7 +6148,6 @@ void mem_cgroup_migrate(struct page *old
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);
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
cgroup-kmemleak-add-kmemleak_free-for-cgroup-deallocations.patch
mm-memcontrol-lockless-page-counters.patch
mm-memcontrol-lockless-page-counters-fix.patch
mm-memcontrol-lockless-page-counters-fix-fix.patch
mm-memcontrol-lockless-page-counters-fix-2.patch
mm-hugetlb_cgroup-convert-to-lockless-page-counters.patch
kernel-res_counter-remove-the-unused-api.patch
kernel-res_counter-remove-the-unused-api-fix.patch
kernel-res_counter-remove-the-unused-api-fix-2.patch
mm-memcontrol-convert-reclaim-iterator-to-simple-css-refcounting.patch
mm-memcontrol-convert-reclaim-iterator-to-simple-css-refcounting-fix.patch
mm-memcontrol-take-a-css-reference-for-each-charged-page.patch
mm-memcontrol-remove-obsolete-kmemcg-pinning-tricks.patch
mm-memcontrol-continue-cache-reclaim-from-offlined-groups.patch
mm-memcontrol-remove-synchroneous-stock-draining-code.patch
mm-vmscan-count-only-dirty-pages-as-congested.patch
memcg-simplify-unreclaimable-groups-handling-in-soft-limit-reclaim.patch
mm-memcontrol-update-mem_cgroup_page_lruvec-documentation.patch
mm-memcontrol-clarify-migration-where-old-page-is-uncharged.patch
memcg-remove-activate_kmem_mutex.patch
mm-memcontrol-micro-optimize-mem_cgroup_update_page_stat.patch
mm-memcontrol-micro-optimize-mem_cgroup_split_huge_fixup.patch
mm-memcontrol-uncharge-pages-on-swapout.patch
mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag.patch
mm-memcontrol-remove-unnecessary-pcg_mem-memory-charge-flag.patch
mm-memcontrol-remove-unnecessary-pcg_used-pc-mem_cgroup-valid-flag.patch
debugging-keep-track-of-page-owners.patch
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