KVM: VMX: Properly return error to userspace on vmentry failure
[linux-2.6.git] / mm / oom_kill.c
index 175a67a..709aedf 100644 (file)
@@ -18,6 +18,7 @@
 #include <linux/oom.h>
 #include <linux/mm.h>
 #include <linux/err.h>
+#include <linux/gfp.h>
 #include <linux/sched.h>
 #include <linux/swap.h>
 #include <linux/timex.h>
@@ -34,6 +35,23 @@ int sysctl_oom_dump_tasks;
 static DEFINE_SPINLOCK(zone_scan_lock);
 /* #define DEBUG */
 
+/*
+ * Is all threads of the target process nodes overlap ours?
+ */
+static int has_intersects_mems_allowed(struct task_struct *tsk)
+{
+       struct task_struct *t;
+
+       t = tsk;
+       do {
+               if (cpuset_mems_allowed_intersects(current, t))
+                       return 1;
+               t = next_thread(t);
+       } while (t != tsk);
+
+       return 0;
+}
+
 /**
  * badness - calculate a numeric value for how bad this task has been
  * @p: task struct of which task we should calculate
@@ -58,7 +76,13 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
        unsigned long points, cpu_time, run_time;
        struct mm_struct *mm;
        struct task_struct *child;
-       int oom_adj;
+       int oom_adj = p->signal->oom_adj;
+       struct task_cputime task_time;
+       unsigned long utime;
+       unsigned long stime;
+
+       if (oom_adj == OOM_DISABLE)
+               return 0;
 
        task_lock(p);
        mm = p->mm;
@@ -66,11 +90,6 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
                task_unlock(p);
                return 0;
        }
-       oom_adj = mm->oom_adj;
-       if (oom_adj == OOM_DISABLE) {
-               task_unlock(p);
-               return 0;
-       }
 
        /*
         * The memory size of the process is the basis for the badness.
@@ -85,7 +104,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
        /*
         * swapoff can easily use up all memory, so kill those first.
         */
-       if (p->flags & PF_SWAPOFF)
+       if (p->flags & PF_OOM_ORIGIN)
                return ULONG_MAX;
 
        /*
@@ -108,8 +127,11 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
          * of seconds. There is no particular reason for this other than
          * that it turned out to work very well in practice.
         */
-       cpu_time = (cputime_to_jiffies(p->utime) + cputime_to_jiffies(p->stime))
-               >> (SHIFT_HZ + 3);
+       thread_group_cputime(p, &task_time);
+       utime = cputime_to_jiffies(task_time.utime);
+       stime = cputime_to_jiffies(task_time.stime);
+       cpu_time = (utime + stime) >> (SHIFT_HZ + 3);
+
 
        if (uptime >= p->start_time.tv_sec)
                run_time = (uptime - p->start_time.tv_sec) >> 10;
@@ -150,7 +172,7 @@ 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_mems_allowed_intersects(current, p))
+       if (!has_intersects_mems_allowed(p))
                points /= 8;
 
        /*
@@ -175,27 +197,46 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 /*
  * Determine the type of allocation constraint.
  */
-static inline enum oom_constraint constrained_alloc(struct zonelist *zonelist,
-                                                   gfp_t gfp_mask)
-{
 #ifdef CONFIG_NUMA
+static enum oom_constraint constrained_alloc(struct zonelist *zonelist,
+                                   gfp_t gfp_mask, nodemask_t *nodemask)
+{
        struct zone *zone;
        struct zoneref *z;
        enum zone_type high_zoneidx = gfp_zone(gfp_mask);
-       nodemask_t nodes = node_states[N_HIGH_MEMORY];
 
-       for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
-               if (cpuset_zone_allowed_softwall(zone, gfp_mask))
-                       node_clear(zone_to_nid(zone), nodes);
-               else
-                       return CONSTRAINT_CPUSET;
+       /*
+        * Reach here only when __GFP_NOFAIL is used. So, we should avoid
+        * to kill current.We have to random task kill in this case.
+        * Hopefully, CONSTRAINT_THISNODE...but no way to handle it, now.
+        */
+       if (gfp_mask & __GFP_THISNODE)
+               return CONSTRAINT_NONE;
 
-       if (!nodes_empty(nodes))
+       /*
+        * The nodemask here is a nodemask passed to alloc_pages(). Now,
+        * cpuset doesn't use this nodemask for its hardwall/softwall/hierarchy
+        * feature. mempolicy is an only user of nodemask here.
+        * check mempolicy's nodemask contains all N_HIGH_MEMORY
+        */
+       if (nodemask && !nodes_subset(node_states[N_HIGH_MEMORY], *nodemask))
                return CONSTRAINT_MEMORY_POLICY;
-#endif
+
+       /* Check this allocation failure is caused by cpuset's wall function */
+       for_each_zone_zonelist_nodemask(zone, z, zonelist,
+                       high_zoneidx, nodemask)
+               if (!cpuset_zone_allowed_softwall(zone, gfp_mask))
+                       return CONSTRAINT_CPUSET;
 
        return CONSTRAINT_NONE;
 }
+#else
+static enum oom_constraint constrained_alloc(struct zonelist *zonelist,
+                               gfp_t gfp_mask, nodemask_t *nodemask)
+{
+       return CONSTRAINT_NONE;
+}
+#endif
 
 /*
  * Simple selection loop. We chose the process with the highest
@@ -206,13 +247,13 @@ static inline enum oom_constraint constrained_alloc(struct zonelist *zonelist,
 static struct task_struct *select_bad_process(unsigned long *ppoints,
                                                struct mem_cgroup *mem)
 {
-       struct task_struct *g, *p;
+       struct task_struct *p;
        struct task_struct *chosen = NULL;
        struct timespec uptime;
        *ppoints = 0;
 
        do_posix_clock_monotonic_gettime(&uptime);
-       do_each_thread(g, p) {
+       for_each_process(p) {
                unsigned long points;
 
                /*
@@ -257,12 +298,15 @@ static struct task_struct *select_bad_process(unsigned long *ppoints,
                        *ppoints = ULONG_MAX;
                }
 
+               if (p->signal->oom_adj == OOM_DISABLE)
+                       continue;
+
                points = badness(p, uptime.tv_sec);
-               if (points > *ppoints) {
+               if (points > *ppoints || !chosen) {
                        chosen = p;
                        *ppoints = points;
                }
-       } while_each_thread(g, p);
+       }
 
        return chosen;
 }
@@ -307,11 +351,30 @@ static void dump_tasks(const struct mem_cgroup *mem)
                }
                printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d     %3d %s\n",
                       p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm,
-                      get_mm_rss(mm), (int)task_cpu(p), mm->oom_adj, p->comm);
+                      get_mm_rss(mm), (int)task_cpu(p), p->signal->oom_adj,
+                      p->comm);
                task_unlock(p);
        } while_each_thread(g, p);
 }
 
+static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
+                                                       struct mem_cgroup *mem)
+{
+       pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, "
+               "oom_adj=%d\n",
+               current->comm, gfp_mask, order, current->signal->oom_adj);
+       task_lock(current);
+       cpuset_print_task_mems_allowed(current);
+       task_unlock(current);
+       dump_stack();
+       mem_cgroup_print_oom_info(mem, p);
+       show_mem();
+       if (sysctl_oom_dump_tasks)
+               dump_tasks(mem);
+}
+
+#define K(x) ((x) << (PAGE_SHIFT-10))
+
 /*
  * 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
@@ -325,12 +388,23 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
                return;
        }
 
-       if (!p->mm)
+       task_lock(p);
+       if (!p->mm) {
+               WARN_ON(1);
+               printk(KERN_WARNING "tried to kill an mm-less task %d (%s)!\n",
+                       task_pid_nr(p), p->comm);
+               task_unlock(p);
                return;
+       }
 
        if (verbose)
-               printk(KERN_ERR "Killed process %d (%s)\n",
-                               task_pid_nr(p), p->comm);
+               printk(KERN_ERR "Killed process %d (%s) "
+                      "vsz:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
+                      task_pid_nr(p), p->comm,
+                      K(p->mm->total_vm),
+                      K(get_mm_counter(p->mm, MM_ANONPAGES)),
+                      K(get_mm_counter(p->mm, MM_FILEPAGES)));
+       task_unlock(p);
 
        /*
         * We give our sacrificial lamb high priority and access to
@@ -345,27 +419,18 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
 
 static int oom_kill_task(struct task_struct *p)
 {
-       struct mm_struct *mm;
-       struct task_struct *g, *q;
-
-       task_lock(p);
-       mm = p->mm;
-       if (!mm || mm->oom_adj == OOM_DISABLE) {
-               task_unlock(p);
+       /* WARNING: mm may not be dereferenced since we did not obtain its
+        * value from get_task_mm(p).  This is OK since all we need to do is
+        * compare mm to q->mm below.
+        *
+        * Furthermore, even if mm contains a non-NULL value, p->mm may
+        * change to NULL at any time since we do not hold task_lock(p).
+        * However, this is of no concern to us.
+        */
+       if (!p->mm || p->signal->oom_adj == OOM_DISABLE)
                return 1;
-       }
-       task_unlock(p);
-       __oom_kill_task(p, 1);
 
-       /*
-        * kill all processes that share the ->mm (i.e. all threads),
-        * but are in a different thread group. Don't let them have access
-        * to memory reserves though, otherwise we might deplete all memory.
-        */
-       do_each_thread(g, q) {
-               if (q->mm == mm && !same_thread_group(q, p))
-                       force_sig(SIGKILL, q);
-       } while_each_thread(g, q);
+       __oom_kill_task(p, 1);
 
        return 0;
 }
@@ -376,27 +441,14 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 {
        struct task_struct *c;
 
-       if (printk_ratelimit()) {
-               task_lock(current);
-               printk(KERN_WARNING "%s invoked oom-killer: "
-                       "gfp_mask=0x%x, order=%d, oom_adj=%d\n",
-                       current->comm, gfp_mask, order,
-                       current->mm ? current->mm->oom_adj : OOM_DISABLE);
-               cpuset_print_task_mems_allowed(current);
-               task_unlock(current);
-               dump_stack();
-               mem_cgroup_print_oom_info(mem, current);
-               show_mem();
-               if (sysctl_oom_dump_tasks)
-                       dump_tasks(mem);
-       }
+       if (printk_ratelimit())
+               dump_header(p, gfp_mask, order, mem);
 
        /*
         * If the task is already exiting, don't alarm the sysadmin or kill
         * its children or threads, just set TIF_MEMDIE so it can die quickly
-        * if its mm is still attached.
         */
-       if (p->mm && (p->flags & PF_EXITING)) {
+       if (p->flags & PF_EXITING) {
                __oom_kill_task(p, 0);
                return 0;
        }
@@ -408,6 +460,8 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
        list_for_each_entry(c, &p->children, sibling) {
                if (c->mm == p->mm)
                        continue;
+               if (mem && !task_in_mem_cgroup(c, mem))
+                       continue;
                if (!oom_kill_task(c))
                        return 0;
        }
@@ -420,15 +474,14 @@ void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask)
        unsigned long points = 0;
        struct task_struct *p;
 
+       if (sysctl_panic_on_oom == 2)
+               panic("out of memory(memcg). panic_on_oom is selected.\n");
        read_lock(&tasklist_lock);
 retry:
        p = select_bad_process(&points, mem);
-       if (PTR_ERR(p) == -1UL)
+       if (!p || 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;
@@ -526,6 +579,7 @@ retry:
        /* Found nothing?!?! Either we hang forever, or we panic. */
        if (!p) {
                read_unlock(&tasklist_lock);
+               dump_header(NULL, gfp_mask, order, NULL);
                panic("Out of memory and no killable processes...\n");
        }
 
@@ -547,13 +601,6 @@ void pagefault_out_of_memory(void)
                /* Got some memory back in the last second. */
                return;
 
-       /*
-        * If this is from memcg, oom-killer is already invoked.
-        * and not worth to go system-wide-oom.
-        */
-       if (mem_cgroup_oom_called(current))
-               goto rest_and_return;
-
        if (sysctl_panic_on_oom)
                panic("out of memory from page fault. panic_on_oom is selected.\n");
 
@@ -565,7 +612,6 @@ void pagefault_out_of_memory(void)
         * Give "p" a good chance of killing itself before we
         * retry to allocate memory.
         */
-rest_and_return:
        if (!test_thread_flag(TIF_MEMDIE))
                schedule_timeout_uninterruptible(1);
 }
@@ -581,7 +627,8 @@ rest_and_return:
  * OR try to be smart about which process to kill. Note that we
  * don't have to be perfect here, we just have to be good.
  */
-void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
+void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
+               int order, nodemask_t *nodemask)
 {
        unsigned long freed = 0;
        enum oom_constraint constraint;
@@ -591,14 +638,16 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
                /* Got some memory back in the last second. */
                return;
 
-       if (sysctl_panic_on_oom == 2)
+       if (sysctl_panic_on_oom == 2) {
+               dump_header(NULL, gfp_mask, order, NULL);
                panic("out of memory. Compulsory panic_on_oom is selected.\n");
+       }
 
        /*
         * Check if there were limitations on the allocation (only relevant for
         * NUMA) that may require different handling.
         */
-       constraint = constrained_alloc(zonelist, gfp_mask);
+       constraint = constrained_alloc(zonelist, gfp_mask, nodemask);
        read_lock(&tasklist_lock);
 
        switch (constraint) {
@@ -608,8 +657,10 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
                break;
 
        case CONSTRAINT_NONE:
-               if (sysctl_panic_on_oom)
+               if (sysctl_panic_on_oom) {
+                       dump_header(NULL, gfp_mask, order, NULL);
                        panic("out of memory. panic_on_oom is selected\n");
+               }
                /* Fall-through */
        case CONSTRAINT_CPUSET:
                __out_of_memory(gfp_mask, order);