memcg: fix oops in oom handling
[sfrench/cifs-2.6.git] / mm / oom_kill.c
index c1850bf991cda9794f6985a7f6ebf595c6adac87..beb592fe9389ffa9fe34c8c92ca82ada55abd960 100644 (file)
 #include <linux/cpuset.h>
 #include <linux/module.h>
 #include <linux/notifier.h>
+#include <linux/memcontrol.h>
 
 int sysctl_panic_on_oom;
 int sysctl_oom_kill_allocating_task;
+int sysctl_oom_dump_tasks;
 static DEFINE_SPINLOCK(zone_scan_mutex);
 /* #define DEBUG */
 
@@ -35,6 +37,7 @@ static DEFINE_SPINLOCK(zone_scan_mutex);
  * badness - calculate a numeric value for how bad this task has been
  * @p: task struct of which task we should calculate
  * @uptime: current uptime in seconds
+ * @mem: target memory controller
  *
  * The formula used is relatively simple and documented inline in the
  * function. The main rationale is that we want to select a good task
@@ -50,7 +53,8 @@ static DEFINE_SPINLOCK(zone_scan_mutex);
  *    of least surprise ... (be careful when you change it)
  */
 
-unsigned long badness(struct task_struct *p, unsigned long uptime)
+unsigned long badness(struct task_struct *p, unsigned long uptime,
+                       struct mem_cgroup *mem)
 {
        unsigned long points, cpu_time, run_time, s;
        struct mm_struct *mm;
@@ -193,7 +197,8 @@ static inline enum oom_constraint constrained_alloc(struct zonelist *zonelist,
  *
  * (not docbooked, we don't want this one cluttering up the manual)
  */
-static struct task_struct *select_bad_process(unsigned long *ppoints)
+static struct task_struct *select_bad_process(unsigned long *ppoints,
+                                               struct mem_cgroup *mem)
 {
        struct task_struct *g, *p;
        struct task_struct *chosen = NULL;
@@ -213,6 +218,8 @@ static struct task_struct *select_bad_process(unsigned long *ppoints)
                /* skip the init task */
                if (is_global_init(p))
                        continue;
+               if (mem && !task_in_mem_cgroup(p, mem))
+                       continue;
 
                /*
                 * This task already has access to memory reserves and is
@@ -247,7 +254,7 @@ static struct task_struct *select_bad_process(unsigned long *ppoints)
                if (p->oomkilladj == OOM_DISABLE)
                        continue;
 
-               points = badness(p, uptime.tv_sec);
+               points = badness(p, uptime.tv_sec, mem);
                if (points > *ppoints || !chosen) {
                        chosen = p;
                        *ppoints = points;
@@ -258,6 +265,44 @@ static struct task_struct *select_bad_process(unsigned long *ppoints)
 }
 
 /**
+ * dump_tasks - dump current memory state of all system tasks
+ * @mem: target memory controller
+ *
+ * Dumps the current memory state of all system tasks, excluding kernel threads.
+ * State information includes task's pid, uid, tgid, vm size, rss, cpu, oom_adj
+ * score, and name.
+ *
+ * If the actual is non-NULL, only tasks that are a member of the mem_cgroup are
+ * shown.
+ *
+ * Call with tasklist_lock read-locked.
+ */
+static void dump_tasks(const struct mem_cgroup *mem)
+{
+       struct task_struct *g, *p;
+
+       printk(KERN_INFO "[ pid ]   uid  tgid total_vm      rss cpu oom_adj "
+              "name\n");
+       do_each_thread(g, p) {
+               /*
+                * total_vm and rss sizes do not exist for tasks with a
+                * detached mm so there's no need to report them.
+                */
+               if (!p->mm)
+                       continue;
+               if (mem && !task_in_mem_cgroup(p, mem))
+                       continue;
+
+               task_lock(p);
+               printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d     %3d %s\n",
+                      p->pid, p->uid, p->tgid, p->mm->total_vm,
+                      get_mm_rss(p->mm), (int)task_cpu(p), p->oomkilladj,
+                      p->comm);
+               task_unlock(p);
+       } while_each_thread(g, p);
+}
+
+/*
  * Send SIGKILL to the selected  process irrespective of  CAP_SYS_RAW_IO
  * flag though it's unlikely that  we select a process with CAP_SYS_RAW_IO
  * set.
@@ -334,7 +379,8 @@ static int oom_kill_task(struct task_struct *p)
 }
 
 static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
-                           unsigned long points, const char *message)
+                           unsigned long points, struct mem_cgroup *mem,
+                           const char *message)
 {
        struct task_struct *c;
 
@@ -344,6 +390,8 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
                        current->comm, gfp_mask, order, current->oomkilladj);
                dump_stack();
                show_mem();
+               if (sysctl_oom_dump_tasks)
+                       dump_tasks(mem);
        }
 
        /*
@@ -368,6 +416,31 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
        return oom_kill_task(p);
 }
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask)
+{
+       unsigned long points = 0;
+       struct task_struct *p;
+
+       cgroup_lock();
+       read_lock(&tasklist_lock);
+retry:
+       p = select_bad_process(&points, mem);
+       if (PTR_ERR(p) == -1UL)
+               goto out;
+
+       if (!p)
+               p = current;
+
+       if (oom_kill_process(p, gfp_mask, 0, points, mem,
+                               "Memory cgroup out of memory"))
+               goto retry;
+out:
+       read_unlock(&tasklist_lock);
+       cgroup_unlock();
+}
+#endif
+
 static BLOCKING_NOTIFIER_HEAD(oom_notify_list);
 
 int register_oom_notifier(struct notifier_block *nb)
@@ -435,6 +508,9 @@ void clear_zonelist_oom(struct zonelist *zonelist)
 
 /**
  * out_of_memory - kill the "best" process when we run out of memory
+ * @zonelist: zonelist pointer
+ * @gfp_mask: memory allocation flags
+ * @order: amount of memory being requested as a power of 2
  *
  * If we run out of memory, we have the choice between either
  * killing a random task (bad), letting the system crash (worse)
@@ -465,7 +541,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
 
        switch (constraint) {
        case CONSTRAINT_MEMORY_POLICY:
-               oom_kill_process(current, gfp_mask, order, points,
+               oom_kill_process(current, gfp_mask, order, points, NULL,
                                "No available memory (MPOL_BIND)");
                break;
 
@@ -475,7 +551,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
                /* Fall-through */
        case CONSTRAINT_CPUSET:
                if (sysctl_oom_kill_allocating_task) {
-                       oom_kill_process(current, gfp_mask, order, points,
+                       oom_kill_process(current, gfp_mask, order, points, NULL,
                                        "Out of memory (oom_kill_allocating_task)");
                        break;
                }
@@ -484,7 +560,7 @@ retry:
                 * Rambo mode: Shoot down a process and hope it solves whatever
                 * issues we may have.
                 */
-               p = select_bad_process(&points);
+               p = select_bad_process(&points, NULL);
 
                if (PTR_ERR(p) == -1UL)
                        goto out;
@@ -495,7 +571,7 @@ retry:
                        panic("Out of memory and no killable processes...\n");
                }
 
-               if (oom_kill_process(p, gfp_mask, order, points,
+               if (oom_kill_process(p, gfp_mask, order, points, NULL,
                                     "Out of memory"))
                        goto retry;