Re: nohz: Update tick instead of restarting tick in tick_nohz_idle_exit()

[Yunfeng Ye]

On 2020/11/27 20:15, Frederic Weisbecker wrote:
> On Mon, Nov 23, 2020 at 09:22:08PM +0800, Yunfeng Ye wrote:
>> In realtime scenarios, the "nohz_full" parameter is configured. Tick
>> interference is not expected when there is only one realtime thread.
>> But when the idle thread is switched to the realtime thread, the tick
>> timer is restarted always.
>>
>> So on the nohz full mode, it is unnecessary to restart the tick timer
>> when there is only one realtime thread. Adding can_stop_full_tick()
>> before restarting the tick, if it return true, keep tick stopped.
>>
>> Signed-off-by: Yunfeng Ye <yeyunfeng@xxxxxxxxxx>
> 
> We can indeed stop the tick and avoid it to be re-armed needlessly at this
> point.
> 
> I'm taking your patch, I may just edit it a little and resend it.
> 
Ok, thanks.

> Thanks!
> .
>