diff options
| author | Fieah Lim <kw@fieahl.im> | 2018-09-11 05:47:25 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2018-09-18 09:32:56 +0200 |
| commit | 7037b43e0076cce1c07c72540e219fb5db7ea01f (patch) | |
| tree | fe6ad1caf17aa94e1bec2891da7423ff00581b52 /drivers/cpuidle | |
| parent | 6a5f95b5a4f4ff29e4071bc5b95f8f3a2aef046b (diff) | |
| download | linux-7037b43e0076cce1c07c72540e219fb5db7ea01f.tar.bz2 | |
cpuidle: enter_state: Don't needlessly calculate diff time
Currently, ktime_us_delta() is invoked unconditionally to compute the
idle residency of the CPU, but it only makes sense to do that if a
valid idle state has been entered, so move the ktime_us_delta()
invocation after the entered_state >= 0 check.
While at it, merge two comment blocks in there into one and drop
a space between type casting of diff.
This patch has no functional changes.
Signed-off-by: Fieah Lim <kw@fieahl.im>
[ rjw: Changelog cleanup, comment format fix ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 6df894d65d9e..4a97446f66d8 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -247,17 +247,17 @@ 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; - 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 { |