[PATCH v2]mm/oom-kill: direct hardware access processes should get bonus

["Figo.zhang" <figo1802@gmail.com>]

 
the victim should not directly access hardware devices like Xorg server,
because the hardware could be left in an unpredictable state, although 
user-application can set /proc/pid/oom_score_adj to protect it. so i think
those processes should get 3% bonus for protection.

in v2, fix the incorrect comment.

Signed-off-by: Figo.zhang <figo1802@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
---
mm/oom_kill.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 4029583..9b06f56 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -196,9 +196,12 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem,
 
 	/*
 	 * Root processes get 3% bonus, just like the __vm_enough_memory()
-	 * implementation used by LSMs.
+	 * implementation used by LSMs. And direct hardware access processes
+	 * also get 3% bonus.
 	 */
-	if (has_capability_noaudit(p, CAP_SYS_ADMIN))
+	if (has_capability_noaudit(p, CAP_SYS_ADMIN) ||
+	    has_capability_noaudit(p, CAP_SYS_RESOURCE) ||
+	    has_capability_noaudit(p, CAP_SYS_RAWIO))
 		points -= 30;
 
 	/*