Re: [PATCH v3] ipc: Update semtimedop() to use hrtimer

From: Prakash Sangappa
Date: Thu Apr 28 2022 - 18:23:57 EST




> On Apr 28, 2022, at 3:02 PM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> On Thu, Apr 28 2022 at 13:50, Davidlohr Bueso wrote:
>> On Thu, 28 Apr 2022, Prakash Sangappa wrote:
>>> - if (timeout)
>>> - jiffies_left = schedule_timeout(jiffies_left);
>>> - else
>>> - schedule();
>>> + timed_out = !schedule_hrtimeout_range(exp,
>>> + current->timer_slack_ns, HRTIMER_MODE_ABS);
>>
>> I'm wondering if the slack parameter instead of passing the timer_slack_ns
>> value immediately, we should do a rt_task() check and pass zero if so.
>
> We should have a wrapper function which takes care of that instead of
> having checks all over the place.

Ok it can be an inline function in sched.h which returns appropriate
slack time. Use that in futex_wait() and sigtimedwait() also in addition to
semtimedop() & mqueue codepath?

Should that be a separate patch?

Thanks,
-Prakash

>
> Thanks,
>
> tglx