Re: [RFT][PATCH v7 6/8] sched: idle: Select idle state before stopping the tick

From: Rafael J. Wysocki
Date: Wed Mar 28 2018 - 06:56:50 EST


On Wed, Mar 28, 2018 at 12:37 PM, Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
> On Wed, Mar 28, 2018 at 10:38 AM, Thomas Ilsche
> <thomas.ilsche@xxxxxxxxxxxxx> wrote:
>> On 2018-03-28 10:13, Rafael J. Wysocki wrote:
>>>

[cut]

>
> So I do
>
> $ for cpu in 0 1 2 3; do taskset -c $cpu sh -c 'while true; do usleep
> 500; done' & done
>
> which is a shell kind of imitation of the above and I cannot see this
> issue at all.
>
> I count the number of times data->next_timer_us in menu_select() is
> greater than TICK_USEC and while this "workload" is running, that
> number is exactly 0.
>
> I'll try with a C program still.

And with a C program I see data->next_timer_us greater than TICK_USEC
while it is running, so let me dig deeper.