diff options
| author | Ingo Molnar <mingo@elte.hu> | 2007-12-04 16:04:39 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-12-04 16:04:39 (GMT) |
| commit | 77034937dc4575ca0a76bf209838ecd39e804089 (patch) | |
| tree | 96713ca12264ead56f859fd3619b27e49072456a /kernel/sched.c | |
| parent | 09b56adc98e0f8a21644fcb4d20ad367c3fceb55 (diff) | |
| download | linux-77034937dc4575ca0a76bf209838ecd39e804089.tar.xz | |
sched: fix crash in sys_sched_rr_get_interval()
Luiz Fernando N. Capitulino reported that sched_rr_get_interval()
crashes for SCHED_OTHER tasks that are on an idle runqueue.
The fix is to return a 0 timeslice for tasks that are on an idle
runqueue. (and which are not running, obviously)
this also shrinks the code a bit:
text data bss dec hex filename
47903 3934 336 52173 cbcd sched.o.before
47885 3934 336 52155 cbbb sched.o.after
Reported-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 59ff6b1..b062856 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4850,17 +4850,21 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval) if (retval) goto out_unlock; - if (p->policy == SCHED_FIFO) - time_slice = 0; - else if (p->policy == SCHED_RR) + /* + * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER + * tasks that are on an otherwise idle runqueue: + */ + time_slice = 0; + if (p->policy == SCHED_RR) { time_slice = DEF_TIMESLICE; - else { + } else { struct sched_entity *se = &p->se; unsigned long flags; struct rq *rq; rq = task_rq_lock(p, &flags); - time_slice = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se)); + if (rq->cfs.load.weight) + time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); task_rq_unlock(rq, &flags); } read_unlock(&tasklist_lock); |