Re: clocksource_watchdog causing scheduling of timers every second (was [v13] support "task_isolation" mode)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Aug 11, 2016 at 06:02:34PM -0500, Christoph Lameter wrote:
> On Thu, 11 Aug 2016, Paul E. McKenney wrote:
> 
> > > With modern Intel we could run it on one CPU per package I think, but at
> > > the same time, too much in NOHZ_FULL assumes the TSC is indeed sane so
> > > it doesn't make sense to me to keep the watchdog running, when it
> > > triggers it would also have to kill all NOHZ_FULL stuff, which would
> > > probably bring the entire machine down..
> >
> > Well, you -could- force a very low priority CPU-bound task to run on
> > all nohz_full CPUs.  Not necessarily a good idea, but a relatively
> > non-intrusive response to that particular error condition.
> 
> Given that we want the cpu only to run the user task I would think that is
> not a good idea.

Heh!  The only really good idea is for clocks to be reliably in sync.

But if they go out of sync, what do you want to do instead?

							Thanx, Paul

--
To unsubscribe from this list: send the line "unsubscribe linux-api" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux