diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-07-27 01:13:26 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-07-29 13:32:29 +0200 |
| commit | 228b30234f258a193317874854eee1ca7807186e (patch) | |
| tree | 826363caecef9df01add91576b80e871207bc437 /drivers/cpuidle | |
| parent | 5ae90d8e467e625e447000cb4335c4db973b1095 (diff) | |
Revert "cpuidle: Quickly notice prediction failure in general case"
Revert commit e11538d1 (cpuidle: Quickly notice prediction failure in
general case), since it depends on commit 69a37be (cpuidle: Quickly
notice prediction failure for repeat mode) that has been identified
as the source of a significant performance regression in v3.8 and
later.
Requested-by: Jeremy Eder <jeder@redhat.com>
Tested-by: Len Brown <len.brown@intel.com>
Cc: 3.8+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/governors/menu.c | 35 |
1 files changed, 1 insertions, 34 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index fe343a06b7d..b69a87e2215 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -34,7 +34,7 @@ static DEFINE_PER_CPU(struct hrtimer, menu_hrtimer); static DEFINE_PER_CPU(int, hrtimer_status); /* menu hrtimer mode */ -enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT, MENU_HRTIMER_GENERAL}; +enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT}; /* * Concepts and ideas behind the menu governor @@ -116,13 +116,6 @@ enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT, MENU_HRTIMER_GENERAL}; * */ -/* - * The C-state residency is so long that is is worthwhile to exit - * from the shallow C-state and re-enter into a deeper C-state. - */ -static unsigned int perfect_cstate_ms __read_mostly = 30; -module_param(perfect_cstate_ms, uint, 0000); - struct menu_device { int last_state_idx; int needs_update; @@ -223,16 +216,6 @@ EXPORT_SYMBOL_GPL(menu_hrtimer_cancel); static enum hrtimer_restart menu_hrtimer_notify(struct hrtimer *hrtimer) { int cpu = smp_processor_id(); - struct menu_device *data = &per_cpu(menu_devices, cpu); - - /* In general case, the expected residency is much larger than - * deepest C-state target residency, but prediction logic still - * predicts a small predicted residency, so the prediction - * history is totally broken if the timer is triggered. - * So reset the correction factor. - */ - if (per_cpu(hrtimer_status, cpu) == MENU_HRTIMER_GENERAL) - data->correction_factor[data->bucket] = RESOLUTION * DECAY; per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP; @@ -389,7 +372,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) /* not deepest C-state chosen for low predicted residency */ if (low_predicted) { unsigned int timer_us = 0; - unsigned int perfect_us = 0; /* * Set a timer to detect whether this sleep is much @@ -400,28 +382,13 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) */ timer_us = 2 * (data->predicted_us + MAX_DEVIATION); - perfect_us = perfect_cstate_ms * 1000; - if (repeat && (4 * timer_us < data->expected_us)) { RCU_NONIDLE(hrtimer_start(hrtmr, ns_to_ktime(1000 * timer_us), HRTIMER_MODE_REL_PINNED)); /* In repeat case, menu hrtimer is started */ per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_REPEAT; - } else if (perfect_us < data->expected_us) { - /* - * The next timer is long. This could be because - * we did not make a useful prediction. - * In that case, it makes sense to re-enter - * into a deeper C-state after some time. - */ - RCU_NONIDLE(hrtimer_start(hrtmr, - ns_to_ktime(1000 * timer_us), - HRTIMER_MODE_REL_PINNED)); - /* In general case, menu hrtimer is started */ - per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_GENERAL; } - } return data->last_state_idx; |