Messages in this thread Patch in this message | | | From | Fieah Lim <> | Subject | [PATCH] cpuidle: enter_state: Don't needlessly calculate diff time | Date | Sat, 8 Sep 2018 02:54:48 +0800 |
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ktime_us_delta() is not that cheap on some platform, and I think this is also the right thing to do. While at it, fix some coding style as well.
Signed-off-by: Fieah Lim <kw@fieahl.im> --- drivers/cpuidle/cpuidle.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 6df894d65d9e..5f6b2c9b6555 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -247,21 +247,20 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, if (!cpuidle_state_is_coupled(drv, index)) local_irq_enable(); - diff = ktime_us_delta(time_end, time_start); - if (diff > INT_MAX) - diff = INT_MAX; - - dev->last_residency = (int) diff; + dev->last_residency = 0; if (entered_state >= 0) { - /* Update cpuidle counters */ - /* This can be moved to within driver enter routine + /* Update cpuidle counters + * This can be moved to within driver enter routine, * but that results in multiple copies of same code. */ + diff = ktime_us_delta(time_end, time_start); + if (diff > INT_MAX) + diff = INT_MAX; + + dev->last_residency = (int)diff; dev->states_usage[entered_state].time += dev->last_residency; dev->states_usage[entered_state].usage++; - } else { - dev->last_residency = 0; } return entered_state; -- 2.18.0
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