@@ -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;
This is a note to let you know that I have just added a patch titled Revert "cpuidle: Quickly notice prediction failure in general case" to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.7. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 68dcd558c7defa0e3df14e4fc5c90d4bab4b7325 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Date: Sat, 27 Jul 2013 01:13:26 +0200 Subject: Revert "cpuidle: Quickly notice prediction failure in general case" commit 228b30234f258a193317874854eee1ca7807186e upstream. 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> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/cpuidle/governors/menu.c | 35 +---------------------------------- 1 file changed, 1 insertion(+), 34 deletions(-) -- 1.8.1.2