diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 97 |
1 files changed, 93 insertions, 4 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d813823ab08..59ffaf511d7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -226,11 +226,26 @@ struct mem_cgroup { bool memsw_is_minimum; /* + * Should we move charges of a task when a task is moved into this + * mem_cgroup ? And what type of charges should we move ? + */ + unsigned long move_charge_at_immigrate; + + /* * statistics. This must be placed at the end of memcg. */ struct mem_cgroup_stat stat; }; +/* Stuffs for move charges at task migration. */ +/* + * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a + * left-shifted bitmap of these types. + */ +enum move_type { + NR_MOVE_TYPE, +}; + /* * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft * limit reclaim to prevent infinite loops, if they ever occur. @@ -2865,6 +2880,31 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) return 0; } +static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, + struct cftype *cft) +{ + return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; +} + +static int mem_cgroup_move_charge_write(struct cgroup *cgrp, + struct cftype *cft, u64 val) +{ + struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); + + if (val >= (1 << NR_MOVE_TYPE)) + return -EINVAL; + /* + * We check this value several times in both in can_attach() and + * attach(), so we need cgroup lock to prevent this value from being + * inconsistent. + */ + cgroup_lock(); + mem->move_charge_at_immigrate = val; + cgroup_unlock(); + + return 0; +} + /* For read statistics */ enum { @@ -3098,6 +3138,11 @@ static struct cftype mem_cgroup_files[] = { .read_u64 = mem_cgroup_swappiness_read, .write_u64 = mem_cgroup_swappiness_write, }, + { + .name = "move_charge_at_immigrate", + .read_u64 = mem_cgroup_move_charge_read, + .write_u64 = mem_cgroup_move_charge_write, + }, }; #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP @@ -3345,6 +3390,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) if (parent) mem->swappiness = get_swappiness(parent); atomic_set(&mem->refcnt, 1); + mem->move_charge_at_immigrate = 0; return &mem->css; free_out: __mem_cgroup_free(mem); @@ -3381,16 +3427,57 @@ static int mem_cgroup_populate(struct cgroup_subsys *ss, return ret; } +/* Handlers for move charge at task migration. */ +static int mem_cgroup_can_move_charge(void) +{ + return 0; +} + +static int mem_cgroup_can_attach(struct cgroup_subsys *ss, + struct cgroup *cgroup, + struct task_struct *p, + bool threadgroup) +{ + int ret = 0; + struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); + + if (mem->move_charge_at_immigrate) { + struct mm_struct *mm; + struct mem_cgroup *from = mem_cgroup_from_task(p); + + VM_BUG_ON(from == mem); + + mm = get_task_mm(p); + if (!mm) + return 0; + + /* We move charges only when we move a owner of the mm */ + if (mm->owner == p) + ret = mem_cgroup_can_move_charge(); + + mmput(mm); + } + return ret; +} + +static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, + struct cgroup *cgroup, + struct task_struct *p, + bool threadgroup) +{ +} + +static void mem_cgroup_move_charge(void) +{ +} + static void mem_cgroup_move_task(struct cgroup_subsys *ss, struct cgroup *cont, struct cgroup *old_cont, struct task_struct *p, bool threadgroup) { - /* - * FIXME: It's better to move charges of this process from old - * memcg to new memcg. But it's just on TODO-List now. - */ + mem_cgroup_move_charge(); } struct cgroup_subsys mem_cgroup_subsys = { @@ -3400,6 +3487,8 @@ struct cgroup_subsys mem_cgroup_subsys = { .pre_destroy = mem_cgroup_pre_destroy, .destroy = mem_cgroup_destroy, .populate = mem_cgroup_populate, + .can_attach = mem_cgroup_can_attach, + .cancel_attach = mem_cgroup_cancel_attach, .attach = mem_cgroup_move_task, .early_init = 0, .use_id = 1, |