Commit ce5f7f82 authored May 12, 2014 by Peter Zijlstra Committed by Ingo Molnar May 22, 2014

sched/deadline: Change sched_getparam() behaviour vs SCHED_DEADLINE



The way we read POSIX one should only call sched_getparam() when
sched_getscheduler() returns either SCHED_FIFO or SCHED_RR.

Given that we currently return sched_param::sched_priority=0 for all
others, extend the same behaviour to SCHED_DEADLINE.

Requested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Dario Faggioli <raistlin@linux.it>
Cc: linux-man <linux-man@vger.kernel.org>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20140512205034.GH13467@laptop.programming.kicks-ass.net


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent dbdb2275

kernel/sched/core.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -3713,7 +3713,7 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
		*/
		SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
		{
		struct sched_param lp;
		struct sched_param lp = { .sched_priority = 0 };
		struct task_struct *p;
		int retval;

		@@ -3730,10 +3730,7 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
		if (retval)
		goto out_unlock;

		if (task_has_dl_policy(p)) {
		retval = -EINVAL;
		goto out_unlock;
		}
		if (task_has_rt_policy(p))
		lp.sched_priority = p->rt_priority;
		rcu_read_unlock();

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