The patch titled
Subject: mm: memcg/slab: cache page number in memcg_(un)charge_slab()
has been added to the -mm tree. Its filename is
mm-memcg-slab-cache-page-number-in-memcg_uncharge_slab.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-slab-cache-page-number-in-memcg_uncharge_slab.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-slab-cache-page-number-in-memcg_uncharge_slab.patch
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------------------------------------------------------
From: Roman Gushchin <guro@xxxxxx>
Subject: mm: memcg/slab: cache page number in memcg_(un)charge_slab()
There are many places in memcg_charge_slab() and memcg_uncharge_slab()
which are calculating the number of pages to charge, css references to
grab etc depending on the order of the slab page.
Let's simplify the code by calculating it once and caching in the local
variable.
Link: http://lkml.kernel.org/r/20200109202659.752357-6-guro@xxxxxx
Signed-off-by: Roman Gushchin <guro@xxxxxx>
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slab.h | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
--- a/mm/slab.h~mm-memcg-slab-cache-page-number-in-memcg_uncharge_slab
+++ a/mm/slab.h
@@ -348,6 +348,7 @@ static __always_inline int memcg_charge_
gfp_t gfp, int order,
struct kmem_cache *s)
{
+ unsigned int nr_pages = 1 << order;
struct mem_cgroup *memcg;
struct lruvec *lruvec;
int ret;
@@ -360,21 +361,21 @@ static __always_inline int memcg_charge_
if (unlikely(!memcg || mem_cgroup_is_root(memcg))) {
mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
- (1 << order));
- percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order);
+ nr_pages);
+ percpu_ref_get_many(&s->memcg_params.refcnt, nr_pages);
return 0;
}
- ret = memcg_kmem_charge_memcg(memcg, gfp, 1 << order);
+ ret = memcg_kmem_charge_memcg(memcg, gfp, nr_pages);
if (ret)
goto out;
lruvec = mem_cgroup_lruvec(memcg, page_pgdat(page));
- mod_lruvec_state(lruvec, cache_vmstat_idx(s), 1 << order);
+ mod_lruvec_state(lruvec, cache_vmstat_idx(s), nr_pages);
/* transer try_charge() page references to kmem_cache */
- percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order);
- css_put_many(&memcg->css, 1 << order);
+ percpu_ref_get_many(&s->memcg_params.refcnt, nr_pages);
+ css_put_many(&memcg->css, nr_pages);
out:
css_put(&memcg->css);
return ret;
@@ -387,6 +388,7 @@ out:
static __always_inline void memcg_uncharge_slab(struct page *page, int order,
struct kmem_cache *s)
{
+ unsigned int nr_pages = 1 << order;
struct mem_cgroup *memcg;
struct lruvec *lruvec;
@@ -394,15 +396,15 @@ static __always_inline void memcg_unchar
memcg = READ_ONCE(s->memcg_params.memcg);
if (likely(!mem_cgroup_is_root(memcg))) {
lruvec = mem_cgroup_lruvec(memcg, page_pgdat(page));
- mod_lruvec_state(lruvec, cache_vmstat_idx(s), -(1 << order));
- memcg_kmem_uncharge_memcg(memcg, order);
+ mod_lruvec_state(lruvec, cache_vmstat_idx(s), -nr_pages);
+ memcg_kmem_uncharge_memcg(memcg, nr_pages);
} else {
mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
- -(1 << order));
+ -nr_pages);
}
rcu_read_unlock();
- percpu_ref_put_many(&s->memcg_params.refcnt, 1 << order);
+ percpu_ref_put_many(&s->memcg_params.refcnt, nr_pages);
}
extern void slab_init_memcg_params(struct kmem_cache *);
_
Patches currently in -mm which might be from guro@xxxxxx are
mm-memcg-slab-introduce-mem_cgroup_from_obj.patch
mm-kmem-cleanup-__memcg_kmem_charge_memcg-arguments.patch
mm-kmem-cleanup-memcg_kmem_uncharge_memcg-arguments.patch
mm-kmem-rename-memcg_kmem_uncharge-into-memcg_kmem_uncharge_page.patch
mm-kmem-switch-to-nr_pages-in-__memcg_kmem_charge_memcg.patch
mm-memcg-slab-cache-page-number-in-memcg_uncharge_slab.patch
mm-kmem-rename-__memcg_kmem_uncharge_memcg-to-__memcg_kmem_uncharge.patch
