powerpc: Convert RTAS event scan from kernel thread to workqueue
RTAS event scan has to run across all cpus. Right now we use a kernel
thread and set_cpus_allowed but in doing so we wake up the previous cpu
unnecessarily.
Some ftrace output shows this:
previous cpu (2):
[002] 7.022331: sched_switch: task swapper:0 [140] ==> rtasd:194 [120]
[002] 7.022338: sched_switch: task rtasd:194 [120] ==> migration/2:9 [0]
[002] 7.022344: sched_switch: task migration/2:9 [0] ==> swapper:0 [140]
next cpu (3):
[003] 7.022345: sched_switch: task swapper:0 [140] ==> rtasd:194 [120]
[003] 7.022371: sched_switch: task rtasd:194 [120] ==> swapper:0 [140]
We can use schedule_delayed_work_on and avoid the unnecessary wakeup.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
1 file changed