diff options
author | David Rientjes <rientjes@google.com> | 2014-03-04 17:55:38 -0800 |
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committer | David Rientjes <rientjes@google.com> | 2014-03-04 17:55:38 -0800 |
commit | 58971a08dd63da910682ea538c7cdfa530036130 (patch) | |
tree | 3331c212bdea304802b72449f40fc7e69d14f1c6 | |
parent | e2058fc1ffacbeb4d83ef128f2784053ef39c745 (diff) | |
download | linux-mm/oom.tar.gz |
mm, memcg: allow system oom killer to be disabledmm/oom
Now that system oom conditions can properly be handled from userspace,
allow the oom killer to be disabled. Otherwise, the kernel will
immediately kill a process and memory will be freed. The userspace oom
handler may have a different policy.
Signed-off-by: David Rientjes <rientjes@google.com>
-rw-r--r-- | Documentation/cgroups/memory.txt | 4 | ||||
-rw-r--r-- | include/linux/memcontrol.h | 6 | ||||
-rw-r--r-- | mm/memcontrol.c | 11 | ||||
-rw-r--r-- | mm/oom_kill.c | 3 |
4 files changed, 19 insertions, 5 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 4ed05d6bdc1dd..4240b0cfb96fe 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -755,8 +755,8 @@ 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 and does -not include the root memcg. +This operation is only allowed to the top cgroup of a sub-hierarchy. If +disabled for the root memcg, the system oom killer is disabled. 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/include/linux/memcontrol.h b/include/linux/memcontrol.h index efa928e36d1d2..68b48ad7b92d8 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -159,6 +159,7 @@ bool mem_cgroup_oom_synchronize(bool wait); extern bool mem_cgroup_alloc_use_oom_reserve(void); extern u64 mem_cgroup_root_oom_reserve(void); extern void mem_cgroup_root_oom_notify(void); +extern bool mem_cgroup_root_oom_disable(void); #ifdef CONFIG_MEMCG_SWAP extern int do_swap_account; @@ -415,6 +416,11 @@ static inline void mem_cgroup_root_oom_notify(void) { } +static inline bool mem_cgroup_root_oom_disable(void) +{ + return false; +} + static inline void mem_cgroup_inc_page_stat(struct page *page, enum mem_cgroup_stat_index idx) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index da4464c02b466..52d04ba38cf14 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5976,13 +5976,13 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, 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))) + /* only 0 and 1 are allowed */ + if (val != !!val) return -EINVAL; mutex_lock(&memcg_create_mutex); /* oom-kill-disable is a flag for subhierarchy. */ - if ((parent->use_hierarchy) || memcg_has_children(memcg)) { + if (parent && (parent->use_hierarchy || memcg_has_children(memcg))) { mutex_unlock(&memcg_create_mutex); return -EINVAL; } @@ -6062,6 +6062,11 @@ u64 mem_cgroup_root_oom_reserve(void) return root_mem_cgroup->oom_reserve >> PAGE_SHIFT; } +bool mem_cgroup_root_oom_disable(void) +{ + return root_mem_cgroup->oom_kill_disable; +} + #ifdef CONFIG_MEMCG_KMEM static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) { diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 329053d3c456f..26aee00e107b0 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -656,6 +656,9 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, mpol_mask = (constraint == CONSTRAINT_MEMORY_POLICY) ? nodemask : NULL; check_panic_on_oom(constraint, gfp_mask, order, mpol_mask); + if (mem_cgroup_root_oom_disable()) + return; + if (sysctl_oom_kill_allocating_task && current->mm && !oom_unkillable_task(current, NULL, nodemask) && current->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) { |