From c61935fd0e7f087a643827b4bf5ef646963c10fa Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 22 Jan 2008 11:24:58 +0100 Subject: [PATCH] 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 --- kernel/sched.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/sched.c b/kernel/sched.c index 37cf07aa4164..e76b11ca6df3 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7153,6 +7153,14 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) { 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; -- 2.20.1