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oom: make oom_score to per-process value

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oom-killer kills a process, not task.  Then oom_score should be calculated
as per-process too.  it makes consistency more and makes speed up
select_bad_process().

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
KOSAKI Motohiro 2009-09-21 17:03:14 -07:00 • committed by Linus Torvalds
commit 495789a51a
3 changed files with 31 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

2
Documentation/filesystems/proc.txt
View file

@ -1205,7 +1205,7 @@ The following heuristics are then applied:
* if the task was reniced, its score doubles
* superuser or direct hardware access tasks (CAP_SYS_ADMIN, CAP_SYS_RESOURCE
or CAP_SYS_RAWIO) have their score divided by 4
* if oom condition happened in one cpuset and checked task does not belong
* if oom condition happened in one cpuset and checked process does not belong
to it, its score is divided by 8
* the resulting score is multiplied by two to the power of oom_adj, i.e.
points <<= oom_adj when it is positive and

2
fs/proc/base.c
View file

@ -447,7 +447,7 @@ static int proc_oom_score(struct task_struct *task, char *buffer)
do_posix_clock_monotonic_gettime(&uptime);
read_lock(&tasklist_lock);
points = badness(task, uptime.tv_sec);
points = badness(task->group_leader, uptime.tv_sec);
read_unlock(&tasklist_lock);
return sprintf(buffer, "%lu\n", points);
}

35
mm/oom_kill.c
View file

@ -34,6 +34,23 @@ 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
@ -59,6 +76,9 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
struct mm_struct *mm;
struct task_struct *child;
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;
@ -106,8 +126,11 @@ 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;
@ -148,7 +171,7 @@ 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;
/*
@ -204,13 +227,13 @@ 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;
/*
@ -263,7 +286,7 @@ static struct task_struct *select_bad_process(unsigned long *ppoints,
chosen = p;
*ppoints = points;
}
} while_each_thread(g, p);
}
return chosen;
}