[PATCH 04/23] sched,acpi_pad: Convert to sched_set_fifo*()

From: Peter Zijlstra
Date: Wed Apr 22 2020 - 07:30:43 EST


Because SCHED_FIFO is a broken scheduler model (see previous patches)
take away the priority field, the kernel can't possibly make an
informed decision.

In this case, use fifo_low, because it only cares about being above
SCHED_NORMAL. Effectively no change in behaviour.

XXX: this driver is still complete crap; why isn't it using proper
idle injection or at the very least play_idle() ?

Cc: rafael.j.wysocki@xxxxxxxxx
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
drivers/acpi/acpi_pad.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -136,12 +136,11 @@ static unsigned int idle_pct = 5; /* per
static unsigned int round_robin_time = 1; /* second */
static int power_saving_thread(void *data)
{
- struct sched_param param = {.sched_priority = 1};
int do_sleep;
unsigned int tsk_index = (unsigned long)data;
u64 last_jiffies = 0;

- sched_setscheduler(current, SCHED_RR, &param);
+ sched_set_fifo_low(current);

while (!kthread_should_stop()) {
unsigned long expire_time;