nfsd4: kill unnecessary check in preprocess_stateid_op
[safe/jmp/linux-2.6] / mm / oom_kill.c
index 00d0bd7..beb592f 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;
-static DEFINE_MUTEX(zone_scan_mutex);
+int sysctl_oom_dump_tasks;
+static DEFINE_SPINLOCK(zone_scan_mutex);
 /* #define DEBUG */
 
 /**
  * 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_MUTEX(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;
@@ -125,8 +129,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
         * Superuser processes are usually more important, so we make it
         * less likely that we kill those.
         */
-       if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_ADMIN) ||
-                               p->uid == 0 || p->euid == 0)
+       if (__capable(p, CAP_SYS_ADMIN) || __capable(p, CAP_SYS_RESOURCE))
                points /= 4;
 
        /*
@@ -135,7 +138,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
         * tend to only have this flag set on applications they think
         * of as important.
         */
-       if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_RAWIO))
+       if (__capable(p, CAP_SYS_RAWIO))
                points /= 4;
 
        /*
@@ -143,7 +146,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
         * because p may have allocated or otherwise mapped memory on
         * this node before. However it will be less likely.
         */
-       if (!cpuset_excl_nodes_overlap(p))
+       if (!cpuset_mems_allowed_intersects(current, p))
                points /= 8;
 
        /*
@@ -194,7 +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;
@@ -212,7 +216,9 @@ static struct task_struct *select_bad_process(unsigned long *ppoints)
                if (!p->mm)
                        continue;
                /* skip the init task */
-               if (is_init(p))
+               if (is_global_init(p))
+                       continue;
+               if (mem && !task_in_mem_cgroup(p, mem))
                        continue;
 
                /*
@@ -248,7 +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;
@@ -259,13 +265,51 @@ 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.
  */
 static void __oom_kill_task(struct task_struct *p, int verbose)
 {
-       if (is_init(p)) {
+       if (is_global_init(p)) {
                WARN_ON(1);
                printk(KERN_WARNING "tried to kill init!\n");
                return;
@@ -278,14 +322,15 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
        }
 
        if (verbose)
-               printk(KERN_ERR "Killed process %d (%s)\n", p->pid, p->comm);
+               printk(KERN_ERR "Killed process %d (%s)\n",
+                               task_pid_nr(p), p->comm);
 
        /*
         * We give our sacrificial lamb high priority and access to
         * all the memory it needs. That way it should be able to
         * exit() and clear out its resources quickly...
         */
-       p->time_slice = HZ;
+       p->rt.time_slice = HZ;
        set_tsk_thread_flag(p, TIF_MEMDIE);
 
        force_sig(SIGKILL, p);
@@ -326,18 +371,28 @@ static int oom_kill_task(struct task_struct *p)
         * to memory reserves though, otherwise we might deplete all memory.
         */
        do_each_thread(g, q) {
-               if (q->mm == mm && q->tgid != p->tgid)
+               if (q->mm == mm && !same_thread_group(q, p))
                        force_sig(SIGKILL, q);
        } while_each_thread(g, q);
 
        return 0;
 }
 
-static int oom_kill_process(struct task_struct *p, unsigned long points,
-               const char *message)
+static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
+                           unsigned long points, struct mem_cgroup *mem,
+                           const char *message)
 {
        struct task_struct *c;
-       struct list_head *tsk;
+
+       if (printk_ratelimit()) {
+               printk(KERN_WARNING "%s invoked oom-killer: "
+                       "gfp_mask=0x%x, order=%d, oomkilladj=%d\n",
+                       current->comm, gfp_mask, order, current->oomkilladj);
+               dump_stack();
+               show_mem();
+               if (sysctl_oom_dump_tasks)
+                       dump_tasks(mem);
+       }
 
        /*
         * If the task is already exiting, don't alarm the sysadmin or kill
@@ -349,11 +404,10 @@ static int oom_kill_process(struct task_struct *p, unsigned long points,
        }
 
        printk(KERN_ERR "%s: kill process %d (%s) score %li or a child\n",
-                                       message, p->pid, p->comm, points);
+                                       message, task_pid_nr(p), p->comm, points);
 
        /* Try to kill a child first */
-       list_for_each(tsk, &p->children) {
-               c = list_entry(tsk, struct task_struct, sibling);
+       list_for_each_entry(c, &p->children, sibling) {
                if (c->mm == p->mm)
                        continue;
                if (!oom_kill_task(c))
@@ -362,6 +416,31 @@ static int oom_kill_process(struct task_struct *p, unsigned long points,
        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)
@@ -388,7 +467,7 @@ int try_set_zone_oom(struct zonelist *zonelist)
 
        z = zonelist->zones;
 
-       mutex_lock(&zone_scan_mutex);
+       spin_lock(&zone_scan_mutex);
        do {
                if (zone_is_oom_locked(*z)) {
                        ret = 0;
@@ -405,7 +484,7 @@ int try_set_zone_oom(struct zonelist *zonelist)
                zone_set_flag(*z, ZONE_OOM_LOCKED);
        } while (*(++z) != NULL);
 out:
-       mutex_unlock(&zone_scan_mutex);
+       spin_unlock(&zone_scan_mutex);
        return ret;
 }
 
@@ -420,15 +499,18 @@ void clear_zonelist_oom(struct zonelist *zonelist)
 
        z = zonelist->zones;
 
-       mutex_lock(&zone_scan_mutex);
+       spin_lock(&zone_scan_mutex);
        do {
                zone_clear_flag(*z, ZONE_OOM_LOCKED);
        } while (*(++z) != NULL);
-       mutex_unlock(&zone_scan_mutex);
+       spin_unlock(&zone_scan_mutex);
 }
 
 /**
  * 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)
@@ -447,14 +529,6 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
                /* Got some memory back in the last second. */
                return;
 
-       if (printk_ratelimit()) {
-               printk(KERN_WARNING "%s invoked oom-killer: "
-                       "gfp_mask=0x%x, order=%d, oomkilladj=%d\n",
-                       current->comm, gfp_mask, order, current->oomkilladj);
-               dump_stack();
-               show_mem();
-       }
-
        if (sysctl_panic_on_oom == 2)
                panic("out of memory. Compulsory panic_on_oom is selected.\n");
 
@@ -463,12 +537,11 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
         * NUMA) that may require different handling.
         */
        constraint = constrained_alloc(zonelist, gfp_mask);
-       cpuset_lock();
        read_lock(&tasklist_lock);
 
        switch (constraint) {
        case CONSTRAINT_MEMORY_POLICY:
-               oom_kill_process(current, points,
+               oom_kill_process(current, gfp_mask, order, points, NULL,
                                "No available memory (MPOL_BIND)");
                break;
 
@@ -478,7 +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, points,
+                       oom_kill_process(current, gfp_mask, order, points, NULL,
                                        "Out of memory (oom_kill_allocating_task)");
                        break;
                }
@@ -487,7 +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;
@@ -495,11 +568,11 @@ retry:
                /* Found nothing?!?! Either we hang forever, or we panic. */
                if (!p) {
                        read_unlock(&tasklist_lock);
-                       cpuset_unlock();
                        panic("Out of memory and no killable processes...\n");
                }
 
-               if (oom_kill_process(p, points, "Out of memory"))
+               if (oom_kill_process(p, gfp_mask, order, points, NULL,
+                                    "Out of memory"))
                        goto retry;
 
                break;
@@ -507,7 +580,6 @@ retry:
 
 out:
        read_unlock(&tasklist_lock);
-       cpuset_unlock();
 
        /*
         * Give "p" a good chance of killing itself before we