From 72788c385604523422592249c19cba0187021e9b Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Tue, 24 May 2011 17:11:40 -0700 Subject: oom: replace PF_OOM_ORIGIN with toggling oom_score_adj There's a kernel-wide shortage of per-process flags, so it's always helpful to trim one when possible without incurring a significant penalty. It's even more important when you're planning on adding a per- process flag yourself, which I plan to do shortly for transparent hugepages. PF_OOM_ORIGIN is used by ksm and swapoff to prefer current since it has a tendency to allocate large amounts of memory and should be preferred for killing over other tasks. We'd rather immediately kill the task making the errant syscall rather than penalizing an innocent task. This patch removes PF_OOM_ORIGIN since its behavior is equivalent to setting the process's oom_score_adj to OOM_SCORE_ADJ_MAX. The process's old oom_score_adj is stored and then set to OOM_SCORE_ADJ_MAX during the time it used to have PF_OOM_ORIGIN. The old value is then reinstated when the process should no longer be considered a high priority for oom killing. Signed-off-by: David Rientjes Reviewed-by: KOSAKI Motohiro Reviewed-by: Minchan Kim Cc: Hugh Dickins Cc: Izik Eidus Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/oom.h | 2 ++ include/linux/sched.h | 1 - 2 files changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/oom.h b/include/linux/oom.h index 5e3aa8311c5..4952fb874ad 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -40,6 +40,8 @@ enum oom_constraint { CONSTRAINT_MEMCG, }; +extern int test_set_oom_score_adj(int new_val); + extern unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem, const nodemask_t *nodemask, unsigned long totalpages); extern int try_set_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_flags); diff --git a/include/linux/sched.h b/include/linux/sched.h index aaf71e08222..44b8faaac7c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1753,7 +1753,6 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t * #define PF_FROZEN 0x00010000 /* frozen for system suspend */ #define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */ #define PF_KSWAPD 0x00040000 /* I am kswapd */ -#define PF_OOM_ORIGIN 0x00080000 /* Allocating much memory to others */ #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */ #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ #define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */ -- cgit v1.2.3-70-g09d2