sched: group scheduler, set uid share fix
setting cpu share to 1 causes hangs, as reported in:
http://bugzilla.kernel.org/show_bug.cgi?id=9779
as the default share is 1024, the values of 0 and 1 can indeed
cause problems. Limit it to 2 or higher values.
These values can only be set by the root user - but still it
makes sense to protect against nonsensical values.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 37cf07a..e76b11c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7153,6 +7153,14 @@
{
int i;
+ /*
+ * A weight of 0 or 1 can cause arithmetics problems.
+ * (The default weight is 1024 - so there's no practical
+ * limitation from this.)
+ */
+ if (shares < 2)
+ shares = 2;
+
spin_lock(&tg->lock);
if (tg->shares == shares)
goto done;
