Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Mon, 10 Sep 2018 23:40:43 +0200 | Subject | Re: [PATCH v2] cpuidle: enter_state: Don't needlessly calculate diff time |
| |
On Mon, Sep 10, 2018 at 11:24 PM Fieah Lim <kw@fieahl.im> wrote: > > On Tue, Sep 11, 2018 at 4:17 AM, Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Mon, Sep 10, 2018 at 7:40 PM Fieah Lim <kw@fieahl.im> wrote: > >> > >> Currently we use ktime_us_delta() to calculate last residency and > >> state usage unconditionally, it makes no sense to do this calculation > >> when we fails to enter any idle state. > >> It can be optimize by moving the calculation after entered_state >= 0 > >> > >> While at it, merge those comment blocks into one and remove a > >> space between type casting of diff. > >> > >> This patch has no functional changes. > >> > >> Signed-off-by: Fieah Lim <kw@fieahl.im> > >> --- > >> Changes from v1: > >> - Rewrite changelog as Rafael J. Wysocki suggested > >> --- > >> 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; > > > > You don't need this line if you retain the "else" branch below, do you? > > > You are right, should I make a v3?
Yes, please.
| |