The oom_adj has been replaced by oom_score_adj in kernel, but the /proc/pid/oom_adj is provided for legacy purposes. When write/read a value into/from /proc/pid/oom_adj, there is a transformation between oom_adj and oom_score_adj.
After writing a new value into /proc/pid/oom_adj, then read it. The return value is a different value than you wrote. Fix this by adding a adjustment factor. Signed-off-by: Hongjie Fang <[email protected]> --- Encountered the problem when I changed a task's oom_adj on an Android smart phone. As follows, 1. # cat /proc/1450/oom_adj 15 2. # echo 10 > /proc/1450/oom_adj 3. # cat /proc/1450/oom_adj 9 diff --git a/fs/proc/base.c b/fs/proc/base.c index b25eee4..2312e43 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1019,15 +1019,19 @@ static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, int oom_adj = OOM_ADJUST_MIN; size_t len; unsigned long flags; + int adjust; if (!task) return -ESRCH; if (lock_task_sighand(task, &flags)) { - if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) + if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) { oom_adj = OOM_ADJUST_MAX; - else - oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / + } else { + adjust = task->signal->oom_score_adj > 0 ? + (OOM_SCORE_ADJ_MAX-1) : -(OOM_SCORE_ADJ_MAX-1); + oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE + adjust) / OOM_SCORE_ADJ_MAX; + } unlock_task_sighand(task, &flags); } put_task_struct(task); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
