proc: fix conversion of oom_score_adj to oom_adj

Ensure that oom_score_adj values are properly converted to
oom_adj values by rounding appropriately.

When there is an attempt to calculate an oom_adj value from its
oom_score_adj value the lack of precision results in an oom_adj
value that is one less than it should be.

For example the oom_adj calculated from oom_score_adj 117 is
calculated as 1.989  (117*17 / 1000), and this is rounded to
1 (and not 2 as it should be).

By properly generating oom_adj values backward compatibility is
better supported.

Change-Id: I7f102cf445e572b8e855a9d6b0cf91e3c438eabf
Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
This commit is contained in:
Liam Mark 2014-04-21 17:16:11 -07:00 committed by Vinayak Menon
parent 3ba1a36ad8
commit 334dad34a6

View file

@ -1018,15 +1018,20 @@ 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 mult = 1;
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) /
OOM_SCORE_ADJ_MAX;
} else {
if (task->signal->oom_score_adj < 0)
mult = -1;
oom_adj = roundup(mult * task->signal->oom_score_adj *
-OOM_DISABLE, OOM_SCORE_ADJ_MAX) /
OOM_SCORE_ADJ_MAX * mult;
}
unlock_task_sighand(task, &flags);
}
put_task_struct(task);