diff options
| -rw-r--r-- | Documentation/cgroups/memory.txt | 11 | ||||
| -rw-r--r-- | mm/memcontrol.c | 29 |
2 files changed, 11 insertions, 29 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 2622115276aa..1829c65f8371 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -535,17 +535,15 @@ Note: 5.3 swappiness -Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. +Similar to /proc/sys/vm/swappiness, but only affecting reclaim that is +triggered by this cgroup's hard limit. The tunable in the root cgroup +corresponds to the global swappiness setting. + Please note that unlike the global swappiness, memcg knob set to 0 really prevents from any swapping even if there is a swap storage available. This might lead to memcg OOM killer if there are no file pages to reclaim. -Following cgroups' swappiness can't be changed. -- root cgroup (uses /proc/sys/vm/swappiness). -- a cgroup which uses hierarchy and it has other cgroup(s) below it. -- a cgroup which uses hierarchy and not the root of hierarchy. - 5.4 failcnt A memory cgroup provides memory.failcnt and memory.memsw.failcnt files. @@ -754,7 +752,6 @@ You can disable the OOM-killer by writing "1" to memory.oom_control file, as: #echo 1 > memory.oom_control -This operation is only allowed to the top cgroup of a sub-hierarchy. If OOM-killer is disabled, tasks under cgroup will hang/sleep in memory cgroup's OOM-waitqueue when they request accountable memory. diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7bab1de50f48..20f47d9cd8b2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5444,22 +5444,14 @@ static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, struct cftype *cft, u64 val) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); - struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css)); - if (val > 100 || !parent) + if (val > 100) return -EINVAL; - mutex_lock(&memcg_create_mutex); - - /* If under hierarchy, only empty-root can set this value */ - if ((parent->use_hierarchy) || memcg_has_children(memcg)) { - mutex_unlock(&memcg_create_mutex); - return -EINVAL; - } - - memcg->swappiness = val; - - mutex_unlock(&memcg_create_mutex); + if (css_parent(css)) + memcg->swappiness = val; + else + vm_swappiness = val; return 0; } @@ -5791,22 +5783,15 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, struct cftype *cft, u64 val) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); - struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css)); /* cannot set to root cgroup and only 0 and 1 are allowed */ - if (!parent || !((val == 0) || (val == 1))) + if (!css_parent(css) || !((val == 0) || (val == 1))) return -EINVAL; - mutex_lock(&memcg_create_mutex); - /* oom-kill-disable is a flag for subhierarchy. */ - if ((parent->use_hierarchy) || memcg_has_children(memcg)) { - mutex_unlock(&memcg_create_mutex); - return -EINVAL; - } memcg->oom_kill_disable = val; if (!val) memcg_oom_recover(memcg); - mutex_unlock(&memcg_create_mutex); + return 0; } |