From: Jing Xiangfeng <jingxiangfeng@huawei.com> hulk inclusion category: feature bugzilla: 51827 CVE: NA -------------------------------------- If parent's qos_level is set, iterate over all cgroups (under this tree) to modify memory.qos_level synchronously. Currently qos_level support 0 and -1. Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com> Reviewed-by: Liu Shixin <liushixin2@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- mm/memcontrol.c | 45 +++++++++++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 18 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 67ce673d6aaa7..ef742a42f105f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3648,6 +3648,23 @@ static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, int sysctl_memcg_qos_stat = DISABLE_MEMCG_QOS; DEFINE_STATIC_KEY_FALSE(memcg_qos_stat_key); +static void memcg_hierarchy_qos_set(struct mem_cgroup *memcg, int val) +{ + struct mem_cgroup *iter; + struct cgroup_subsys_state *css; + + if (!memcg) + memcg = root_mem_cgroup; + + rcu_read_lock(); + css_for_each_descendant_pre(css, &memcg->css) { + iter = mem_cgroup_from_css(css); + + iter->memcg_priority = val; + } + rcu_read_unlock(); +} + static void memcg_qos_init(struct mem_cgroup *memcg) { struct mem_cgroup *parent = parent_mem_cgroup(memcg); @@ -3679,10 +3696,15 @@ static int memcg_qos_write(struct cgroup_subsys_state *css, if (!static_branch_likely(&memcg_qos_stat_key)) return -EACCES; - if (val >= 0) - memcg->memcg_priority = 0; - else - memcg->memcg_priority = -1; + if (mem_cgroup_is_root(memcg)) + return -EINVAL; + + if (val != 0 && val != -1) + return -EINVAL; + + memcg->memcg_priority = val; + if (memcg->use_hierarchy) + memcg_hierarchy_qos_set(memcg, val); return 0; } @@ -3773,19 +3795,6 @@ void memcg_print_bad_task(void *arg, int ret) } } -static void memcg_qos_reset(void) -{ - struct mem_cgroup *iter; - struct cgroup_subsys_state *css; - - rcu_read_lock(); - css_for_each_descendant_pre(css, &root_mem_cgroup->css) { - iter = mem_cgroup_from_css(css); - iter->memcg_priority = 0; - } - rcu_read_unlock(); -} - int sysctl_memcg_qos_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { @@ -3800,7 +3809,7 @@ int sysctl_memcg_qos_handler(struct ctl_table *table, int write, pr_info("enable memcg priority.\n"); } else { static_branch_disable(&memcg_qos_stat_key); - memcg_qos_reset(); + memcg_hierarchy_qos_set(NULL, 0); pr_info("disable memcg priority.\n"); } } -- 2.25.1