[Devel] [PATCH rh7 1/3] memcg: add oom_guarantee
Kirill Tkhai
ktkhai at odin.com
Thu May 28 09:21:21 PDT 2015
В Чт, 21/05/2015 в 12:50 +0300, Vladimir Davydov пишет:
> OOM guarantee works exactly like low limit, but for OOM, i.e. tasks
> inside cgroups above the limit are killed first.
>
> Read/write via memory.oom_guarantee.
>
> Signed-off-by: Vladimir Davydov <vdavydov at parallels.com>
Reviewed-by: Kirill Tkhai <ktkhai at odin.com>
> ---
> include/linux/memcontrol.h | 6 +++
> include/linux/oom.h | 2 +-
> mm/memcontrol.c | 97 +++++++++++++++++++++++++++++++++++++++++++-
> mm/oom_kill.c | 14 ++++++-
> 4 files changed, 114 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 5507be5af34f..1bab6f0e2b38 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -120,6 +120,7 @@ bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);
> int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
> unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list);
> void mem_cgroup_update_lru_size(struct lruvec *, enum lru_list, int);
> +extern bool mem_cgroup_below_oom_guarantee(struct task_struct *p);
> extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
> struct task_struct *p);
> extern void mem_cgroup_replace_page_cache(struct page *oldpage,
> @@ -342,6 +343,11 @@ mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
> {
> }
>
> +static inline bool mem_cgroup_below_oom_guarantee(struct task_struct *p)
> +{
> + return false;
> +}
> +
> static inline void
> mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
> {
> diff --git a/include/linux/oom.h b/include/linux/oom.h
> index c13af3feba30..17100d02e8d3 100644
> --- a/include/linux/oom.h
> +++ b/include/linux/oom.h
> @@ -67,7 +67,7 @@ extern void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask,
>
> extern enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
> unsigned long totalpages, const nodemask_t *nodemask,
> - bool force_kill);
> + bool force_kill, bool ignore_memcg_guarantee);
>
> extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
> int order, nodemask_t *mask, bool force_kill);
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 75add1495418..8e4331340571 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -284,6 +284,8 @@ struct mem_cgroup {
> atomic_long_t mem_failcnt;
> atomic_long_t swap_failcnt;
>
> + unsigned long long oom_guarantee;
> +
> /*
> * Should the accounting and control be hierarchical, per subtree?
> */
> @@ -1550,6 +1552,51 @@ bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg)
> return true;
> }
>
> +static bool __mem_cgroup_below_oom_guarantee(struct mem_cgroup *root,
> + struct mem_cgroup *memcg)
> +{
> + if (mem_cgroup_disabled())
> + return false;
> +
> + if (memcg == root_mem_cgroup)
> + return false;
> +
> + if (res_counter_read_u64(&memcg->memsw, RES_USAGE) >=
> + memcg->oom_guarantee)
> + return false;
> +
> + while (memcg != root) {
> + memcg = parent_mem_cgroup(memcg);
> + if (!memcg)
> + break;
> +
> + if (memcg == root_mem_cgroup)
> + break;
> +
> + if (res_counter_read_u64(&memcg->memsw, RES_USAGE) >=
> + memcg->oom_guarantee)
> + return false;
> + }
> + return true;
> +}
> +
> +bool mem_cgroup_below_oom_guarantee(struct task_struct *p)
> +{
> + struct mem_cgroup *memcg = NULL;
> + bool ret = false;
> +
> + p = find_lock_task_mm(p);
> + if (p) {
> + memcg = try_get_mem_cgroup_from_mm(p->mm);
> + task_unlock(p);
> + }
> + if (memcg) {
> + ret = __mem_cgroup_below_oom_guarantee(root_mem_cgroup, memcg);
> + css_put(&memcg->css);
> + }
> + return ret;
> +}
> +
> #define mem_cgroup_from_res_counter(counter, member) \
> container_of(counter, struct mem_cgroup, member)
>
> @@ -1838,6 +1885,7 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
> unsigned long totalpages;
> unsigned int points = 0;
> struct task_struct *chosen = NULL;
> + bool ignore_memcg_guarantee = false;
>
> /*
> * If current has a pending SIGKILL or is exiting, then automatically
> @@ -1851,15 +1899,20 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
>
> check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
> totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1;
> +retry:
> for_each_mem_cgroup_tree(iter, memcg) {
> struct cgroup *cgroup = iter->css.cgroup;
> struct cgroup_iter it;
> struct task_struct *task;
>
> + if (!ignore_memcg_guarantee &&
> + __mem_cgroup_below_oom_guarantee(memcg, iter))
> + continue;
> +
> cgroup_iter_start(cgroup, &it);
> while ((task = cgroup_iter_next(cgroup, &it))) {
> switch (oom_scan_process_thread(task, totalpages, NULL,
> - false)) {
> + false, true)) {
> case OOM_SCAN_SELECT:
> if (chosen)
> put_task_struct(chosen);
> @@ -1890,8 +1943,13 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
> cgroup_iter_end(cgroup, &it);
> }
>
> - if (!chosen)
> + if (!chosen) {
> + if (!ignore_memcg_guarantee) {
> + ignore_memcg_guarantee = true;
> + goto retry;
> + }
> return;
> + }
> points = chosen_points * 1000 / totalpages;
> oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
> NULL, "Memory cgroup out of memory");
> @@ -5054,6 +5112,36 @@ static int mem_cgroup_low_write(struct cgroup *cont, struct cftype *cft,
> return 0;
> }
>
> +static ssize_t mem_cgroup_oom_guarantee_read(struct cgroup *cont,
> + struct cftype *cft, struct file *file, char __user *buf,
> + size_t nbytes, loff_t *ppos)
> +{
> + struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
> + char str[64];
> + int len;
> +
> + len = scnprintf(str, sizeof(str), "%llu\n", memcg->oom_guarantee);
> + return simple_read_from_buffer(buf, nbytes, ppos, str, len);
> +}
> +
> +static int mem_cgroup_oom_guarantee_write(struct cgroup *cont,
> + struct cftype *cft, const char *buffer)
> +{
> + struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
> + unsigned long long val;
> + int ret;
> +
> + if (mem_cgroup_is_root(memcg))
> + return -EINVAL;
> +
> + ret = res_counter_memparse_write_strategy(buffer, &val);
> + if (ret)
> + return ret;
> +
> + memcg->oom_guarantee = val;
> + return 0;
> +}
> +
> static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
> unsigned long long *mem_limit, unsigned long long *memsw_limit)
> {
> @@ -5956,6 +6044,11 @@ static struct cftype mem_cgroup_files[] = {
> .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
> },
> {
> + .name = "oom_guarantee",
> + .write_string = mem_cgroup_oom_guarantee_write,
> + .read = mem_cgroup_oom_guarantee_read,
> + },
> + {
> .name = "pressure_level",
> .register_event = vmpressure_register_event,
> .unregister_event = vmpressure_unregister_event,
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index 61c8693215da..a6928b4939cc 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -256,7 +256,7 @@ static enum oom_constraint constrained_alloc(struct zonelist *zonelist,
>
> enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
> unsigned long totalpages, const nodemask_t *nodemask,
> - bool force_kill)
> + bool force_kill, bool ignore_memcg_guarantee)
> {
> if (task->exit_state)
> return OOM_SCAN_CONTINUE;
> @@ -291,6 +291,10 @@ enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
> if (!(task->group_leader->ptrace & PT_TRACE_EXIT))
> return OOM_SCAN_ABORT;
> }
> +
> + if (!ignore_memcg_guarantee && mem_cgroup_below_oom_guarantee(task))
> + return OOM_SCAN_CONTINUE;
> +
> return OOM_SCAN_OK;
> }
>
> @@ -307,13 +311,15 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
> struct task_struct *g, *p;
> struct task_struct *chosen = NULL;
> unsigned long chosen_points = 0;
> + bool ignore_memcg_guarantee = false;
>
> rcu_read_lock();
> +retry:
> for_each_process_thread(g, p) {
> unsigned int points;
>
> switch (oom_scan_process_thread(p, totalpages, nodemask,
> - force_kill)) {
> + force_kill, ignore_memcg_guarantee)) {
> case OOM_SCAN_SELECT:
> chosen = p;
> chosen_points = ULONG_MAX;
> @@ -334,6 +340,10 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
> }
> if (chosen)
> get_task_struct(chosen);
> + else if (!ignore_memcg_guarantee) {
> + ignore_memcg_guarantee = true;
> + goto retry;
> + }
> rcu_read_unlock();
>
> *ppoints = chosen_points * 1000 / totalpages;
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