[Devel] [PATCH RHEL7 COMMIT] memcg: allow to disable cleancache per memcg
Konstantin Khorenko
khorenko at virtuozzo.com
Tue Oct 20 04:59:31 PDT 2015
The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.8.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-229.7.2.vz7.8.8
------>
commit 6157411c658b2aa2702432b018bd679a017e5416
Author: Vladimir Davydov <vdavydov at virtuozzo.com>
Date: Tue Oct 20 15:59:31 2015 +0400
memcg: allow to disable cleancache per memcg
Currently, it is only possible to disable tcache system-wide, but it
might be useful to disable it for a particular container while leaving
it enabled for others, e.g. in case the container is known to generate
tons of used-once page cache (backup).
This patch introduces memory.disable_cleancache per memcg knob. Writing
1 to it disables cleancache for the corresponding cgroup. Cleancache may
be re-enabled by writing 0 to it.
https://jira.sw.ru/browse/PSBM-34163
Signed-off-by: Vladimir Davydov <vdavydov at virtuozzo.com>
Reviewed-by: Kirill Tkhai <ktkhai at viztuozzo.com>
---
include/linux/memcontrol.h | 6 ++++
mm/cleancache.c | 10 +++++--
mm/memcontrol.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 85 insertions(+), 2 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 0c85642..5835c8c 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -118,6 +118,7 @@ void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
*/
int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec);
bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);
+bool mem_cgroup_cleancache_disabled(struct page *page);
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list);
void mem_cgroup_update_lru_size(struct lruvec *, enum lru_list, int);
@@ -353,6 +354,11 @@ static inline bool mem_cgroup_low(struct mem_cgroup *root,
return false;
}
+static inline bool mem_cgroup_cleancache_disabled(struct page *page)
+{
+ return false;
+}
+
static inline unsigned long
mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
{
diff --git a/mm/cleancache.c b/mm/cleancache.c
index a3308bc..16fc1d7 100644
--- a/mm/cleancache.c
+++ b/mm/cleancache.c
@@ -15,6 +15,7 @@
#include <linux/fs.h>
#include <linux/exportfs.h>
#include <linux/mm.h>
+#include <linux/memcontrol.h>
#include <linux/debugfs.h>
#include <linux/cleancache.h>
@@ -227,8 +228,13 @@ void __cleancache_put_page(struct page *page)
pool_id = page->mapping->host->i_sb->cleancache_poolid;
if (pool_id >= 0 &&
cleancache_get_key(page->mapping->host, &key) >= 0) {
- cleancache_ops->put_page(pool_id, key, page->index, page);
- cleancache_puts++;
+ if (!mem_cgroup_cleancache_disabled(page)) {
+ cleancache_ops->put_page(pool_id, key,
+ page->index, page);
+ cleancache_puts++;
+ } else
+ cleancache_ops->invalidate_page(pool_id, key,
+ page->index);
}
}
EXPORT_SYMBOL(__cleancache_put_page);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 14e6aee..234ed8d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -315,6 +315,20 @@ struct mem_cgroup {
/* set when res.limit == memsw.limit */
bool memsw_is_minimum;
+#ifdef CONFIG_CLEANCACHE
+ /*
+ * cleancache_disabled_toggle: toggled by writing to
+ * memory.disable_cleancache
+ *
+ * cleancache_disabled: set iff cleancache_disabled_toggle is
+ * set in this cgroup or any of its ascendants; controls whether
+ * cleancache callback is called when a page is evicted from
+ * this cgroup
+ */
+ bool cleancache_disabled_toggle;
+ bool cleancache_disabled;
+#endif
+
/* protect arrays of thresholds */
struct mutex thresholds_lock;
@@ -1578,6 +1592,27 @@ bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg)
return true;
}
+#ifdef CONFIG_CLEANCACHE
+bool mem_cgroup_cleancache_disabled(struct page *page)
+{
+ struct page_cgroup *pc;
+ bool ret = false;
+
+ if (mem_cgroup_disabled())
+ return false;
+
+ pc = lookup_page_cgroup(page);
+ if (!PageCgroupUsed(pc))
+ return false;
+
+ lock_page_cgroup(pc);
+ if (likely(PageCgroupUsed(pc)))
+ ret = pc->mem_cgroup->cleancache_disabled;
+ unlock_page_cgroup(pc);
+ return ret;
+}
+#endif
+
void mem_cgroup_note_oom_kill(struct mem_cgroup *root_memcg,
struct task_struct *task)
{
@@ -5191,6 +5226,31 @@ static int mem_cgroup_oom_guarantee_write(struct cgroup *cont,
return 0;
}
+#ifdef CONFIG_CLEANCACHE
+static u64 mem_cgroup_disable_cleancache_read(struct cgroup *cgrp,
+ struct cftype *cft)
+{
+ return mem_cgroup_from_cont(cgrp)->cleancache_disabled_toggle;
+}
+
+static int mem_cgroup_disable_cleancache_write(struct cgroup *cgrp,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup *iter, *parent;
+
+ mutex_lock(&memcg_create_mutex);
+ memcg->cleancache_disabled_toggle = !!val;
+ for_each_mem_cgroup_tree(iter, memcg) {
+ parent = parent_mem_cgroup(iter);
+ iter->cleancache_disabled = parent->cleancache_disabled ||
+ iter->cleancache_disabled_toggle;
+ }
+ mutex_unlock(&memcg_create_mutex);
+ return 0;
+}
+#endif
+
static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
unsigned long long *mem_limit, unsigned long long *memsw_limit)
{
@@ -6131,6 +6191,14 @@ static struct cftype mem_cgroup_files[] = {
.read_seq_string = memcg_numa_stat_show,
},
#endif
+#ifdef CONFIG_CLEANCACHE
+ {
+ .name = "disable_cleancache",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_u64 = mem_cgroup_disable_cleancache_read,
+ .write_u64 = mem_cgroup_disable_cleancache_write,
+ },
+#endif
#ifdef CONFIG_MEMCG_KMEM
{
.name = "kmem.limit_in_bytes",
@@ -6385,6 +6453,9 @@ mem_cgroup_css_online(struct cgroup *cont)
memcg->use_hierarchy = parent->use_hierarchy;
memcg->oom_kill_disable = parent->oom_kill_disable;
memcg->swappiness = mem_cgroup_swappiness(parent);
+#ifdef CONFIG_CLEANCACHE
+ memcg->cleancache_disabled = parent->cleancache_disabled;
+#endif
if (parent->use_hierarchy) {
res_counter_init(&memcg->res, &parent->res);
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