linux-2.6-debug-vm-would-have-oomkilled.patch

   1 diff --git a/kernel/sysctl.c b/kernel/sysctl.c
   2 index b2a2d68..3b132ee 100644
   3 --- a/kernel/sysctl.c
   4 +++ b/kernel/sysctl.c
   5 @@ -67,6 +67,7 @@ extern int sysctl_overcommit_ratio;
   6  extern int sysctl_panic_on_oom;
   7  extern int sysctl_oom_kill_allocating_task;
   8  extern int sysctl_oom_dump_tasks;
   9 +extern int sysctl_would_have_oomkilled;
  10  extern int max_threads;
  11  extern int core_uses_pid;
  12  extern int suid_dumpable;
  13 @@ -861,6 +862,14 @@ static struct ctl_table vm_table[] = {
  14                 .proc_handler   = &proc_dointvec,
  15         },
  16         {
  17 +               .ctl_name       = CTL_UNNUMBERED,
  18 +               .procname       = "would_have_oomkilled",
  19 +               .data           = &sysctl_would_have_oomkilled,
  20 +               .maxlen         = sizeof(sysctl_would_have_oomkilled),
  21 +               .mode           = 0644,
  22 +               .proc_handler   = &proc_dointvec,
  23 +       },
  24 +       {
  25                 .ctl_name       = VM_OVERCOMMIT_RATIO,
  26                 .procname       = "overcommit_ratio",
  27                 .data           = &sysctl_overcommit_ratio,
  28 diff --git a/mm/oom_kill.c b/mm/oom_kill.c
  29 index f255eda..3335a94 100644
  30 --- a/mm/oom_kill.c
  31 +++ b/mm/oom_kill.c
  32 @@ -31,6 +31,7 @@
  33  int sysctl_panic_on_oom;
  34  int sysctl_oom_kill_allocating_task;
  35  int sysctl_oom_dump_tasks;
  36 +int sysctl_would_have_oomkilled;
  37  static DEFINE_SPINLOCK(zone_scan_lock);
  38  /* #define DEBUG */
  39
  40 @@ -321,6 +322,12 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
  41                 return;
  42         }
  43
  44 +       if (sysctl_would_have_oomkilled == 1) {
  45 +               printk(KERN_ERR "Would have killed process %d (%s). But continuing instead.\n",
  46 +                               task_pid_nr(p), p->comm);
  47 +               return;
  48 +       }
  49 +
  50         if (verbose)
  51                 printk(KERN_ERR "Killed process %s(%d:#%u)\n",
  52                         p->comm, task_pid_nr(p), p->xid);
  53 @@ -363,6 +370,12 @@ static int oom_kill_task(struct task_struct *p)
  54                         return 1;
  55         } while_each_thread(g, q);
  56
  57 +       if (sysctl_would_have_oomkilled == 1) {
  58 +               printk(KERN_ERR "Would have killed process %d (%s). But continuing instead.\n",
  59 +                               task_pid_nr(p), p->comm);
  60 +               return 1;
  61 +       }
  62 +
  63         __oom_kill_task(p, 1);
  64
  65         /*