From 39fd8fd22b3224ec6819d33b3e34ae4da6a35f05 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 15 Jan 2014 16:33:20 +0100 Subject: [PATCH] sched: Fix up scheduler syscall LTP fails Wu reported LTP failures: > ltp.sched_setparam02.1.TFAIL > ltp.sched_setparam02.2.TFAIL > ltp.sched_setparam02.3.TFAIL > ltp.sched_setparam03.1.TFAIL There were 2 things wrong; firstly __setscheduler() failed on sched_setparam()'s policy = -1, fix that by reading from p->policy in that case. Secondly, getparam() (and getattr()) would still report !0 sched_priority for !FIFO/RR tasks after having been such. So unconditionally set p->rt_priority. Reported-by: Fengguang Wu Signed-off-by: Peter Zijlstra Cc: Juri Lelli Cc: Dario Faggioli Fixes: d50dde5a10f3 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Link: http://lkml.kernel.org/r/20140115153320.GH31570@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c1b3d7e..e9212eb 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3172,15 +3172,23 @@ static void __setscheduler(struct rq *rq, struct task_struct *p, { int policy = attr->sched_policy; + if (policy == -1) /* setparam */ + policy = p->policy; + p->policy = policy; if (dl_policy(policy)) __setparam_dl(p, attr); - else if (rt_policy(policy)) - p->rt_priority = attr->sched_priority; - else + else if (fair_policy(policy)) p->static_prio = NICE_TO_PRIO(attr->sched_nice); + /* + * __sched_setscheduler() ensures attr->sched_priority == 0 when + * !rt_policy. Always setting this ensures that things like + * getparam()/getattr() don't report silly values for !rt tasks. + */ + p->rt_priority = attr->sched_priority; + p->normal_prio = normal_prio(p); p->prio = rt_mutex_getprio(p); -- 2.7.4