[GIT PULL] scheduler fixes

Ingo Molnar
2014-03-16T16:36:52Z

Linus,

Please pull the latest sched-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-for-linus

# HEAD: 96b3d28bf4b00f62fc8386ff5d487d1830793a3d sched/clock: Prevent tracing recursion in sched_clock_cpu()

Three small fixes.

Thanks,

Ingo

------------------>
Fernando Luis Vazquez Cao (1):
sched/clock: Prevent tracing recursion in sched_clock_cpu()

Juri Lelli (1):
sched/deadline: Deny unprivileged users to set/change SCHED_DEADLINE policy

Peter Zijlstra (1):
stop_machine: Fix^2 race between stop_two_cpus() and stop_cpus()

kernel/sched/clock.c | 4 ++--
kernel/sched/core.c | 9 +++++++++
kernel/stop_machine.c | 2 +-
3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index 43c2bcc..b30a292 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -301,14 +301,14 @@ u64 sched_clock_cpu(int cpu)
if (unlikely(!sched_clock_running))
return 0ull;

- preempt_disable();
+ preempt_disable_notrace();
scd = cpu_sdc(cpu);

if (cpu != smp_processor_id())
clock = sched_clock_remote(scd);
else
clock = sched_clock_local(scd);
- preempt_enable();
+ preempt_enable_notrace();

return clock;
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6edbef2..f5c6635 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3338,6 +3338,15 @@ recheck:
return -EPERM;
}

+ /*
+ * Can't set/change SCHED_DEADLINE policy at all for now
+ * (safest behavior); in the future we would like to allow
+ * unprivileged DL tasks to increase their relative deadline
+ * or reduce their runtime (both ways reducing utilization)
+ */
+ if (dl_policy(policy))
+ return -EPERM;
+
/*
* Treat SCHED_IDLE as nice 20. Only allow a switch to
* SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 84571e0..01fbae5 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -293,7 +293,7 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
*/
smp_call_function_single(min(cpu1, cpu2),
&irq_cpu_stop_queue_work,
- &call_args, 0);
+ &call_args, 1);
lg_local_unlock(&stop_cpus_lock);
preempt_enable();