From 6e6d6efabd2567337f7d97791f7a60aa5fdbcfc2 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 21 Apr 2020 12:09:13 +0200 Subject: sched,psci: Convert to sched_set_fifo*() 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. Effectively changes prio from 99 to 50. XXX this thing is horrific, it basically open-codes a stop-machine and idle. Cc: daniel.lezcano@linaro.org Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Ingo Molnar Acked-by: Valentin Schneider Tested-by: Sudeep Holla --- drivers/firmware/psci/psci_checker.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) (limited to 'drivers/firmware/psci') diff --git a/drivers/firmware/psci/psci_checker.c b/drivers/firmware/psci/psci_checker.c index 873841af8d57..a5279a430274 100644 --- a/drivers/firmware/psci/psci_checker.c +++ b/drivers/firmware/psci/psci_checker.c @@ -272,7 +272,6 @@ static int suspend_test_thread(void *arg) { int cpu = (long)arg; int i, nb_suspend = 0, nb_shallow_sleep = 0, nb_err = 0; - struct sched_param sched_priority = { .sched_priority = MAX_RT_PRIO-1 }; struct cpuidle_device *dev; struct cpuidle_driver *drv; /* No need for an actual callback, we just want to wake up the CPU. */ @@ -282,9 +281,8 @@ static int suspend_test_thread(void *arg) wait_for_completion(&suspend_threads_started); /* Set maximum priority to preempt all other threads on this CPU. */ - if (sched_setscheduler_nocheck(current, SCHED_FIFO, &sched_priority)) - pr_warn("Failed to set suspend thread scheduler on CPU %d\n", - cpu); + if (sched_set_fifo(current)) + pr_warn("Failed to set suspend thread scheduler on CPU %d\n", cpu); dev = this_cpu_read(cpuidle_devices); drv = cpuidle_get_cpu_driver(dev); @@ -349,11 +347,6 @@ static int suspend_test_thread(void *arg) if (atomic_dec_return_relaxed(&nb_active_threads) == 0) complete(&suspend_threads_done); - /* Give up on RT scheduling and wait for termination. */ - sched_priority.sched_priority = 0; - if (sched_setscheduler_nocheck(current, SCHED_NORMAL, &sched_priority)) - pr_warn("Failed to set suspend thread scheduler on CPU %d\n", - cpu); for (;;) { /* Needs to be set first to avoid missing a wakeup. */ set_current_state(TASK_INTERRUPTIBLE); -- cgit From 8b700983de82f79e05b2c1136d6513ea4c9b22c4 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 22 Apr 2020 13:10:04 +0200 Subject: sched: Remove sched_set_*() return value Ingo suggested that since the new sched_set_*() functions are implemented using the 'nocheck' variants, they really shouldn't ever fail, so remove the return value. Cc: axboe@kernel.dk Cc: daniel.lezcano@linaro.org Cc: sudeep.holla@arm.com Cc: airlied@redhat.com Cc: broonie@kernel.org Cc: paulmck@kernel.org Suggested-by: Ingo Molnar Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Ingo Molnar --- drivers/firmware/psci/psci_checker.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/firmware/psci') diff --git a/drivers/firmware/psci/psci_checker.c b/drivers/firmware/psci/psci_checker.c index a5279a430274..6fff482847e7 100644 --- a/drivers/firmware/psci/psci_checker.c +++ b/drivers/firmware/psci/psci_checker.c @@ -281,8 +281,7 @@ static int suspend_test_thread(void *arg) wait_for_completion(&suspend_threads_started); /* Set maximum priority to preempt all other threads on this CPU. */ - if (sched_set_fifo(current)) - pr_warn("Failed to set suspend thread scheduler on CPU %d\n", cpu); + sched_set_fifo(current); dev = this_cpu_read(cpuidle_devices); drv = cpuidle_get_cpu_driver(dev); -- cgit