diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2008-02-18 13:39:37 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-19 19:44:57 +0200 |
| commit | 79b3feffb10417f197d2ab48dd4fa3c0c9e7d788 (patch) | |
| tree | 78b754d36beddd15f43723faa861e06b239ca47b /kernel/sched_fair.c | |
| parent | 19fb518c2a0c5d88ed22bba7083b7e7bc2a9c231 (diff) | |
| download | lwn-79b3feffb10417f197d2ab48dd4fa3c0c9e7d788.tar.gz lwn-79b3feffb10417f197d2ab48dd4fa3c0c9e7d788.zip | |
sched: fix regression with sched yield
Balbir Singh reported:
> 1:mon> t
> [c0000000e7677da0] c000000000067de0 .sys_sched_yield+0x6c/0xbc
> [c0000000e7677e30] c000000000008748 syscall_exit+0x0/0x40
> --- Exception: c01 (System Call) at 00000400001d09e4
> SP (4000664cb10) is in userspace
> 1:mon> r
> cpu 0x1: Vector: 300 (Data Access) at [c0000000e7677aa0]
> pc: c000000000068e50: .yield_task_fair+0x94/0xc4
> lr: c000000000067de0: .sys_sched_yield+0x6c/0xbc
the check that should have avoided that is:
/*
* Are we the only task in the tree?
*/
if (unlikely(rq->load.weight == curr->se.load.weight))
return;
But I guess that overlooks rt tasks, they also increase the load.
So I guess something like this ought to fix it..
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | kernel/sched_fair.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index bedda18f37a5..290cf770b712 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -904,7 +904,7 @@ static void yield_task_fair(struct rq *rq) /* * Already in the rightmost position? */ - if (unlikely(rightmost->vruntime < se->vruntime)) + if (unlikely(!rightmost || rightmost->vruntime < se->vruntime)) return; /* |