Re: [PATCH 2/3] timer: Check thread timers only when there are active thread timers

From: Jason Low
Date: Wed Aug 26 2015 - 13:41:43 EST


On Wed, 2015-08-26 at 13:04 -0400, George Spelvin wrote:
> - check_thread_timers(tsk, &firing);
> + if (!task_cputime_zero(&tsk->cputime_expires))
> + check_thread_timers(tsk, &firing);
>
> Sincere question; I'm not certain myself: would it make more sense to put
> this shortcut into check_thread_timers()?
>
> It seems more like an optimization of that function than something the
> caller needs to know about.

Yes, I also thought it might be better if we add something like:

if (task_cputime_zero(&tsk->cputime_expires)
return;

in check_thread_timers(). The reason I made it this way though is
because in the next few lines, we do a similar check before calling
check_process_timers(), and I wanted to keep things consistent.

However, perhaps we can consider also moving that
tsk->signal->cputimer.running check into check_process_timers() too.

Thanks for the suggestions.

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