Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit df381975 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

memcg: get_mem_cgroup_from_mm() 



Instead of returning NULL from try_get_mem_cgroup_from_mm() when the mm
owner is exiting, just return root_mem_cgroup.  This makes sense for all
callsites and gets rid of some of them having to fallback manually.

[fengguang.wu@intel.com: fix warnings]
Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarFengguang Wu <fengguang.wu@intel.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 03583f1a

include/linux/memcontrol.h

+0 −6
Original line number Diff line number Diff line
@@ -94,7 +94,6 @@ bool task_in_mem_cgroup(struct task_struct *task, 


extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);

extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);

extern struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm);



extern struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);

extern struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css);
@@ -294,11 +293,6 @@ static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) 
	return NULL;

}



static inline struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)

{

	return NULL;

}



static inline bool mm_match_cgroup(struct mm_struct *mm,

		struct mem_cgroup *memcg)

{

mm/memcontrol.c

+4 −14
Original line number Diff line number Diff line
@@ -1071,7 +1071,7 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) 
	return mem_cgroup_from_css(task_css(p, memory_cgrp_id));

}



struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)

static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)

{

	struct mem_cgroup *memcg = NULL;
@@ -1079,7 +1079,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) 
	do {

		memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));

		if (unlikely(!memcg))

			break;

			memcg = root_mem_cgroup;

	} while (!css_tryget(&memcg->css));

	rcu_read_unlock();

	return memcg;
@@ -1475,7 +1475,7 @@ bool task_in_mem_cgroup(struct task_struct *task, 


	p = find_lock_task_mm(task);

	if (p) {

		curr = try_get_mem_cgroup_from_mm(p->mm);

		curr = get_mem_cgroup_from_mm(p->mm);

		task_unlock(p);

	} else {

		/*
@@ -1489,8 +1489,6 @@ bool task_in_mem_cgroup(struct task_struct *task, 
			css_get(&curr->css);

		rcu_read_unlock();

	}

	if (!curr)

		return false;

	/*

	 * We should check use_hierarchy of "memcg" not "curr". Because checking

	 * use_hierarchy of "curr" here make this function true if hierarchy is
@@ -3617,15 +3615,7 @@ __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) 
	if (!current->mm || current->memcg_kmem_skip_account)

		return true;



	memcg = try_get_mem_cgroup_from_mm(current->mm);



	/*

	 * very rare case described in mem_cgroup_from_task. Unfortunately there

	 * isn't much we can do without complicating this too much, and it would

	 * be gfp-dependent anyway. Just let it go

	 */

	if (unlikely(!memcg))

		return true;

	memcg = get_mem_cgroup_from_mm(current->mm);



	if (!memcg_can_account_kmem(memcg)) {

		css_put(&memcg->css);