diff options
| -rw-r--r-- | Documentation/cgroups/memory.txt | 23 | ||||
| -rw-r--r-- | mm/memcontrol.c | 113 |
2 files changed, 117 insertions, 19 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index eac22d3..44e7ded3 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -493,6 +493,8 @@ It's applicable for root and non-root cgroup. 10. OOM Control +memory.oom_control file is for OOM notification and other controls. + Memory controler implements oom notifier using cgroup notification API (See cgroups.txt). It allows to register multiple oom notification delivery and gets notification when oom happens. @@ -505,6 +507,27 @@ To register a notifier, application need: Application will be notifier through eventfd when oom happens. OOM notification doesn't work for root cgroup. +You can disable 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 subhierarchy. +If oom-killer is disabled, tasks under cgroup will hang/sleep +in memcg's oom-waitq when they request accountable memory. + +For running them, you have to relax the memcg's oom sitaution by + * enlarge limit or reduce usage. +To reduce usage, + * kill some tasks. + * move some tasks to other group with account migration. + * remove some files (on tmpfs?) + +Then, stopped tasks will work again. + +At reading, current status of OOM is shown. + oom_kill_disable 0 or 1 (if 1, oom-killer is disabled) + under_oom 0 or 1 (if 1, the memcg is under OOM,tasks may + be stopped.) 11. TODO diff --git a/mm/memcontrol.c b/mm/memcontrol.c index da2ed39..53eb30e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -214,6 +214,8 @@ struct mem_cgroup { atomic_t refcnt; unsigned int swappiness; + /* OOM-Killer disable */ + int oom_kill_disable; /* set when res.limit == memsw.limit */ bool memsw_is_minimum; @@ -235,7 +237,6 @@ struct mem_cgroup { * mem_cgroup ? And what type of charges should we move ? */ unsigned long move_charge_at_immigrate; - /* * percpu counter. */ @@ -1342,20 +1343,26 @@ static void memcg_wakeup_oom(struct mem_cgroup *mem) __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem); } +static void memcg_oom_recover(struct mem_cgroup *mem) +{ + if (mem->oom_kill_disable && atomic_read(&mem->oom_lock)) + memcg_wakeup_oom(mem); +} + /* * try to call OOM killer. returns false if we should exit memory-reclaim loop. */ bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask) { struct oom_wait_info owait; - bool locked; + bool locked, need_to_kill; owait.mem = mem; owait.wait.flags = 0; owait.wait.func = memcg_oom_wake_function; owait.wait.private = current; INIT_LIST_HEAD(&owait.wait.task_list); - + need_to_kill = true; /* At first, try to OOM lock hierarchy under mem.*/ mutex_lock(&memcg_oom_mutex); locked = mem_cgroup_oom_lock(mem); @@ -1364,15 +1371,17 @@ bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask) * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL * under OOM is always welcomed, use TASK_KILLABLE here. */ - if (!locked) - prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); - else + prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); + if (!locked || mem->oom_kill_disable) + need_to_kill = false; + if (locked) mem_cgroup_oom_notify(mem); mutex_unlock(&memcg_oom_mutex); - if (locked) + if (need_to_kill) { + finish_wait(&memcg_oom_waitq, &owait.wait); mem_cgroup_out_of_memory(mem, mask); - else { + } else { schedule(); finish_wait(&memcg_oom_waitq, &owait.wait); } @@ -2162,15 +2171,6 @@ __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype) /* If swapout, usage of swap doesn't decrease */ if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) uncharge_memsw = false; - /* - * do_batch > 0 when unmapping pages or inode invalidate/truncate. - * In those cases, all pages freed continously can be expected to be in - * the same cgroup and we have chance to coalesce uncharges. - * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) - * because we want to do uncharge as soon as possible. - */ - if (!current->memcg_batch.do_batch || test_thread_flag(TIF_MEMDIE)) - goto direct_uncharge; batch = ¤t->memcg_batch; /* @@ -2181,6 +2181,17 @@ __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype) if (!batch->memcg) batch->memcg = mem; /* + * do_batch > 0 when unmapping pages or inode invalidate/truncate. + * In those cases, all pages freed continously can be expected to be in + * the same cgroup and we have chance to coalesce uncharges. + * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) + * because we want to do uncharge as soon as possible. + */ + + if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) + goto direct_uncharge; + + /* * In typical case, batch->memcg == mem. This means we can * merge a series of uncharges to an uncharge of res_counter. * If not, we uncharge res_counter ony by one. @@ -2196,6 +2207,8 @@ direct_uncharge: res_counter_uncharge(&mem->res, PAGE_SIZE); if (uncharge_memsw) res_counter_uncharge(&mem->memsw, PAGE_SIZE); + if (unlikely(batch->memcg != mem)) + memcg_oom_recover(mem); return; } @@ -2332,6 +2345,7 @@ void mem_cgroup_uncharge_end(void) res_counter_uncharge(&batch->memcg->res, batch->bytes); if (batch->memsw_bytes) res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes); + memcg_oom_recover(batch->memcg); /* forget this pointer (for sanity check) */ batch->memcg = NULL; } @@ -2568,10 +2582,11 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val) { int retry_count; - u64 memswlimit; + u64 memswlimit, memlimit; int ret = 0; int children = mem_cgroup_count_children(memcg); u64 curusage, oldusage; + int enlarge; /* * For keeping hierarchical_reclaim simple, how long we should retry @@ -2582,6 +2597,7 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); + enlarge = 0; while (retry_count) { if (signal_pending(current)) { ret = -EINTR; @@ -2599,6 +2615,11 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, mutex_unlock(&set_limit_mutex); break; } + + memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); + if (memlimit < val) + enlarge = 1; + ret = res_counter_set_limit(&memcg->res, val); if (!ret) { if (memswlimit == val) @@ -2620,6 +2641,8 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, else oldusage = curusage; } + if (!ret && enlarge) + memcg_oom_recover(memcg); return ret; } @@ -2628,9 +2651,10 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, unsigned long long val) { int retry_count; - u64 memlimit, oldusage, curusage; + u64 memlimit, memswlimit, oldusage, curusage; int children = mem_cgroup_count_children(memcg); int ret = -EBUSY; + int enlarge = 0; /* see mem_cgroup_resize_res_limit */ retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; @@ -2652,6 +2676,9 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, mutex_unlock(&set_limit_mutex); break; } + memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); + if (memswlimit < val) + enlarge = 1; ret = res_counter_set_limit(&memcg->memsw, val); if (!ret) { if (memlimit == val) @@ -2674,6 +2701,8 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, else oldusage = curusage; } + if (!ret && enlarge) + memcg_oom_recover(memcg); return ret; } @@ -2865,6 +2894,7 @@ move_account: if (ret) break; } + memcg_oom_recover(mem); /* it seems parent cgroup doesn't have enough mem */ if (ret == -ENOMEM) goto try_to_free; @@ -3645,6 +3675,46 @@ static int mem_cgroup_oom_unregister_event(struct cgroup *cgrp, return 0; } +static int mem_cgroup_oom_control_read(struct cgroup *cgrp, + struct cftype *cft, struct cgroup_map_cb *cb) +{ + struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); + + cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable); + + if (atomic_read(&mem->oom_lock)) + cb->fill(cb, "under_oom", 1); + else + cb->fill(cb, "under_oom", 0); + return 0; +} + +/* + */ +static int mem_cgroup_oom_control_write(struct cgroup *cgrp, + struct cftype *cft, u64 val) +{ + struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); + struct mem_cgroup *parent; + + /* cannot set to root cgroup and only 0 and 1 are allowed */ + if (!cgrp->parent || !((val == 0) || (val == 1))) + return -EINVAL; + + parent = mem_cgroup_from_cont(cgrp->parent); + + cgroup_lock(); + /* oom-kill-disable is a flag for subhierarchy. */ + if ((parent->use_hierarchy) || + (mem->use_hierarchy && !list_empty(&cgrp->children))) { + cgroup_unlock(); + return -EINVAL; + } + mem->oom_kill_disable = val; + cgroup_unlock(); + return 0; +} + static struct cftype mem_cgroup_files[] = { { .name = "usage_in_bytes", @@ -3702,6 +3772,8 @@ static struct cftype mem_cgroup_files[] = { }, { .name = "oom_control", + .read_map = mem_cgroup_oom_control_read, + .write_u64 = mem_cgroup_oom_control_write, .register_event = mem_cgroup_oom_register_event, .unregister_event = mem_cgroup_oom_unregister_event, .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), @@ -3943,6 +4015,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) } else { parent = mem_cgroup_from_cont(cont->parent); mem->use_hierarchy = parent->use_hierarchy; + mem->oom_kill_disable = parent->oom_kill_disable; } if (parent && parent->use_hierarchy) { @@ -4215,6 +4288,7 @@ static void mem_cgroup_clear_mc(void) if (mc.precharge) { __mem_cgroup_cancel_charge(mc.to, mc.precharge); mc.precharge = 0; + memcg_oom_recover(mc.to); } /* * we didn't uncharge from mc.from at mem_cgroup_move_account(), so @@ -4223,6 +4297,7 @@ static void mem_cgroup_clear_mc(void) if (mc.moved_charge) { __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); mc.moved_charge = 0; + memcg_oom_recover(mc.from); } /* we must fixup refcnts and charges */ if (mc.moved_swap) { |
