Commit 334dad34 authored Apr 21, 2014 by Liam Mark Committed by Vinayak Menon Feb 16, 2017

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>

parent 3ba1a36a

fs/proc/base.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -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);