Commit 87a2560d authored by Jinjiang Tu's avatar Jinjiang Tu
Browse files

mm/memcontrol: add ksm state for memcg 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9GT87



----------------------------------------

Add KSM state for memcg, the valid values include 0 and 1.

When changing auto_ksm_enabled from 0 to 1, enable KSM for tasks in the
memcg. When changing auto_ksm_enabled from 1 to 0, disable KSM for tasks
in the memcg. If enable/disable fails, return the error code and don't
change auto_ksm_enabled. If the auto_ksm_state of the child memcgs differ,
also enable/disable KSM for the tasks in the memcgs. If enable/disable
for a child memcg fails, stop traversing child memcgs and return the
error code.

When writing the value same to auto_ksm_enabled of the memcg, i.e. from 0
to 0 and 1 to 1, do nothing.

Signed-off-by: default avatarJinjiang Tu <tujinjiang@huawei.com>
parent c5723c0b

include/linux/memcontrol.h

+4 −0
Original line number Diff line number Diff line
@@ -414,7 +414,11 @@ struct mem_cgroup { 
#else

	KABI_RESERVE(7)

#endif

#ifdef CONFIG_KSM

	KABI_USE(8, bool auto_ksm_enabled)

#else

	KABI_RESERVE(8)

#endif



	struct mem_cgroup_per_node *nodeinfo[0];

	/* WARNING: nodeinfo must be the last member here */

mm/memcontrol.c

+29 −1
Original line number Diff line number Diff line
@@ -5772,7 +5772,7 @@ static ssize_t memcg_high_async_ratio_write(struct kernfs_open_file *of, 
}



#ifdef CONFIG_KSM

static int memcg_set_ksm_for_tasks(struct mem_cgroup *memcg, bool enable)

static int __memcg_set_ksm_for_tasks(struct mem_cgroup *memcg, bool enable)

{

	struct task_struct *task;

	struct mm_struct *mm;
@@ -5806,6 +5806,27 @@ static int memcg_set_ksm_for_tasks(struct mem_cgroup *memcg, bool enable) 
	return ret;

}



static int memcg_set_ksm_for_tasks(struct mem_cgroup *memcg, bool enable)

{

	struct mem_cgroup *iter;

	int ret = 0;



	for_each_mem_cgroup_tree(iter, memcg) {

		if (READ_ONCE(iter->auto_ksm_enabled) == enable)

			continue;



		ret = __memcg_set_ksm_for_tasks(iter, enable);

		if (ret) {

			mem_cgroup_iter_break(memcg, iter);

			break;

		}



		WRITE_ONCE(iter->auto_ksm_enabled, enable);

	}



	return ret;

}



static int memory_ksm_show(struct seq_file *m, void *v)

{

	unsigned long ksm_merging_pages = 0;
@@ -5833,6 +5854,7 @@ static int memory_ksm_show(struct seq_file *m, void *v) 
	}

	css_task_iter_end(&it);



	seq_printf(m, "auto ksm enabled: %d\n", READ_ONCE(memcg->auto_ksm_enabled));

	seq_printf(m, "merge any tasks: %u\n", tasks);

	seq_printf(m, "ksm_rmap_items %lu\n", ksm_rmap_items);

	seq_printf(m, "ksm_merging_pages %lu\n", ksm_merging_pages);
@@ -5855,6 +5877,9 @@ static ssize_t memory_ksm_write(struct kernfs_open_file *of, char *buf, 
	if (err)

		return err;



	if (READ_ONCE(memcg->auto_ksm_enabled) == enable)

		return nbytes;



	err = memcg_set_ksm_for_tasks(memcg, enable);

	if (err)

		return err;
@@ -6430,6 +6455,9 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) 
	}



	hugetlb_pool_inherit(memcg, parent);

#ifdef CONFIG_KSM

	memcg->auto_ksm_enabled = READ_ONCE(parent->auto_ksm_enabled);

#endif



	error = memcg_online_kmem(memcg);

	if (error)