linux/drivers/cpuidle/poll_state.c
Peter Zijlstra 4d627628d7 cpuidle: Fix poll_idle() noinstr annotation
The instrumentation_begin()/end() annotations in poll_idle() were
complete nonsense. Specifically they caused tracing to happen in the
middle of noinstr code, resulting in RCU splats.

Now that local_clock() is noinstr, mark up the rest and let it rip.

Fixes: 00717eb8c9 ("cpuidle: Annotate poll_idle()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/oe-lkp/202301192148.58ece903-oliver.sang@intel.com
Link: https://lore.kernel.org/r/20230126151323.819534689@infradead.org
2023-01-31 15:01:47 +01:00

63 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* poll_state.c - Polling idle state
*/
#include <linux/cpuidle.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <linux/sched/idle.h>
#define POLL_IDLE_RELAX_COUNT 200
static int __cpuidle poll_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
u64 time_start;
time_start = local_clock();
dev->poll_time_limit = false;
raw_local_irq_enable();
if (!current_set_polling_and_test()) {
unsigned int loop_count = 0;
u64 limit;
limit = cpuidle_poll_time(drv, dev);
while (!need_resched()) {
cpu_relax();
if (loop_count++ < POLL_IDLE_RELAX_COUNT)
continue;
loop_count = 0;
if (local_clock() - time_start > limit) {
dev->poll_time_limit = true;
break;
}
}
}
raw_local_irq_disable();
current_clr_polling();
return index;
}
void cpuidle_poll_state_init(struct cpuidle_driver *drv)
{
struct cpuidle_state *state = &drv->states[0];
snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
state->exit_latency = 0;
state->target_residency = 0;
state->exit_latency_ns = 0;
state->target_residency_ns = 0;
state->power_usage = -1;
state->enter = poll_idle;
state->flags = CPUIDLE_FLAG_POLLING;
}
EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);