mm: invoke oom-killer from remaining unconverted page fault handlers

A few remaining architectures directly kill the page faulting task in an
out of memory situation.  This is usually not a good idea since that task
might not even use a significant amount of memory and so may not be the
optimal victim to resolve the situation.

Since 2.6.29's 1c0fe6e ("mm: invoke oom-killer from page fault") there is
a hook that architecture page fault handlers are supposed to call to
invoke the OOM killer and let it pick the right task to kill.  Convert the
remaining architectures over to this hook.

To have the previous behavior of simply taking out the faulting task the
vm.oom_kill_allocating_task sysctl can be set to 1.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>   [arch/arc bits]
Cc: James Hogan <james.hogan@imgtec.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 318164cabdfc5e72c771d5f686aad2da49e63d8f..0fd1f0d515ffb394f64107ceb1ecdfb856a8858d 100644 (file)
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -207,8 +207,10 @@ out_of_memory:
        }
        up_read(&mm->mmap_sem);
 
-       if (user_mode(regs))
-               do_group_exit(SIGKILL); /* This will never return */
+       if (user_mode(regs)) {
+               pagefault_out_of_memory();
+               return;
+       }
 
        goto no_context;
 

diff --git a/arch/metag/mm/fault.c b/arch/metag/mm/fault.c
index 2c75bf7357c58deec87850b5cf293d510ddd9743..8fddf46e6c62f3d7570a65d5d0034a185e46985e 100644 (file)
--- a/arch/metag/mm/fault.c
+++ b/arch/metag/mm/fault.c
@@ -224,8 +224,10 @@ do_sigbus:
         */
 out_of_memory:
        up_read(&mm->mmap_sem);
-       if (user_mode(regs))
-               do_group_exit(SIGKILL);
+       if (user_mode(regs)) {
+               pagefault_out_of_memory();
+               return 1;
+       }
 
 no_context:
        /* Are we prepared to handle this kernel fault?  */

diff --git a/arch/mn10300/mm/fault.c b/arch/mn10300/mm/fault.c
index d48a84fd7fae51b298ee1b03956dd823dd82ffdf..8a2e6ded9a4465e247890166f6a9ddadd25c7987 100644 (file)
--- a/arch/mn10300/mm/fault.c
+++ b/arch/mn10300/mm/fault.c
@@ -345,9 +345,10 @@ no_context:
  */
 out_of_memory:
        up_read(&mm->mmap_sem);
-       printk(KERN_ALERT "VM: killing process %s\n", tsk->comm);
-       if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR)
-               do_exit(SIGKILL);
+       if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR) {
+               pagefault_out_of_memory();
+               return;
+       }
        goto no_context;
 
 do_sigbus:

diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
index e2bfafce66c53661064e2cf5e4b0d5d036e2c6a7..4a41f8493ab0b4d9276a05315884d076fb440db9 100644 (file)
--- a/arch/openrisc/mm/fault.c
+++ b/arch/openrisc/mm/fault.c
@@ -267,10 +267,10 @@ out_of_memory:
        __asm__ __volatile__("l.nop 1");
 
        up_read(&mm->mmap_sem);
-       printk("VM: killing process %s\n", tsk->comm);
-       if (user_mode(regs))
-               do_exit(SIGKILL);
-       goto no_context;
+       if (!user_mode(regs))
+               goto no_context;
+       pagefault_out_of_memory();
+       return;
 
 do_sigbus:
        up_read(&mm->mmap_sem);

diff --git a/arch/score/mm/fault.c b/arch/score/mm/fault.c
index 47b600e4b2c50ae853b72404f3e1b051dce15f53..6b18fb0189ae4ff0d06fea13b717b42a8f58c664 100644 (file)
--- a/arch/score/mm/fault.c
+++ b/arch/score/mm/fault.c
@@ -172,10 +172,10 @@ out_of_memory:
                down_read(&mm->mmap_sem);
                goto survive;
        }
-       printk("VM: killing process %s\n", tsk->comm);
-       if (user_mode(regs))
-               do_group_exit(SIGKILL);
-       goto no_context;
+       if (!user_mode(regs))
+               goto no_context;
+       pagefault_out_of_memory();
+       return;
 
 do_sigbus:
        up_read(&mm->mmap_sem);

diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index 3d2b81c163a6aac89e0e32d862bd603021eec917..f7f99f90cbe0ebf7630416814daf846490e525eb 100644 (file)
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -573,10 +573,10 @@ out_of_memory:
                down_read(&mm->mmap_sem);
                goto survive;
        }
-       pr_alert("VM: killing process %s\n", tsk->comm);
-       if (!is_kernel_mode)
-               do_group_exit(SIGKILL);
-       goto no_context;
+       if (is_kernel_mode)
+               goto no_context;
+       pagefault_out_of_memory();
+       return 0;
 
 do_sigbus:
        up_read(&mm->mmap_sem);