printk/sched: Introduce special printk_sched() for those awkward moments
There's a few awkward printk()s inside of scheduler guts that people
prefer to keep but really are rather deadlock prone. Fudge around it
by storing the text in a per-cpu buffer and poll it using the existing
printk_tick() handler.
This will drop output when its more frequent than once a tick, however
only the affinity thing could possible go that fast and for that just
one should suffice to notify the admin he's done something silly..
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-wua3lmkt3dg8nfts66o6brne@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b1ccce8..8781cec 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1284,7 +1284,7 @@
* leave kernel.
*/
if (p->mm && printk_ratelimit()) {
- printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n",
+ printk_sched("process %d (%s) no longer affine to cpu%d\n",
task_pid_nr(p), p->comm, cpu);
}
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 7f7e7cd..b60dad7 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -864,8 +864,14 @@
* but accrue some time due to boosting.
*/
if (likely(rt_b->rt_runtime)) {
+ static bool once = false;
+
rt_rq->rt_throttled = 1;
- printk_once(KERN_WARNING "sched: RT throttling activated\n");
+
+ if (!once) {
+ once = true;
+ printk_sched("sched: RT throttling activated\n");
+ }
} else {
/*
* In case we did anyway, make it go away,