diff options
Diffstat (limited to 'drivers/cpuidle/driver.c')
| -rw-r--r-- | drivers/cpuidle/driver.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index d9cda7f6ccb9..370664c47e65 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -8,6 +8,8 @@ * This code is licenced under the GPL. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/mutex.h> #include <linux/module.h> #include <linux/sched.h> @@ -16,6 +18,7 @@ #include <linux/cpumask.h> #include <linux/tick.h> #include <linux/cpu.h> +#include <linux/math64.h> #include "cpuidle.h" @@ -187,11 +190,19 @@ static void __cpuidle_driver_init(struct cpuidle_driver *drv) s->target_residency = div_u64(s->target_residency_ns, NSEC_PER_USEC); if (s->exit_latency > 0) - s->exit_latency_ns = s->exit_latency * NSEC_PER_USEC; + s->exit_latency_ns = mul_u32_u32(s->exit_latency, NSEC_PER_USEC); else if (s->exit_latency_ns < 0) s->exit_latency_ns = 0; else s->exit_latency = div_u64(s->exit_latency_ns, NSEC_PER_USEC); + + /* + * Warn if the exit latency of a CPU idle state exceeds its + * target residency which is assumed to never happen in cpuidle + * in multiple places. + */ + if (s->exit_latency_ns > s->target_residency_ns) + pr_warn("Idle state %d target residency too low\n", i); } } @@ -260,7 +271,7 @@ static void __cpuidle_unregister_driver(struct cpuidle_driver *drv) * @drv: a pointer to a valid struct cpuidle_driver * * Register the driver under a lock to prevent concurrent attempts to - * [un]register the driver from occuring at the same time. + * [un]register the driver from occurring at the same time. * * Returns 0 on success, a negative error code (returned by * __cpuidle_register_driver()) otherwise. @@ -295,7 +306,7 @@ EXPORT_SYMBOL_GPL(cpuidle_register_driver); * @drv: a pointer to a valid struct cpuidle_driver * * Unregisters the cpuidle driver under a lock to prevent concurrent attempts - * to [un]register the driver from occuring at the same time. @drv has to + * to [un]register the driver from occurring at the same time. @drv has to * match the currently registered driver. */ void cpuidle_unregister_driver(struct cpuidle_driver *drv) |