Messages in this thread | | | Date | Tue, 16 Jul 2013 03:01:36 +0200 | From | Frederic Weisbecker <> | Subject | Re: nohz: Warn if the machine can not perform nohz_full |
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On Mon, Jul 15, 2013 at 01:24:23PM -0400, Dave Jones wrote: > On Mon, Jul 15, 2013 at 07:18:02PM +0200, Frederic Weisbecker wrote: > > > > So I guess you guys never want this to be enabled on distro kernels ? > > > If that's the case, can you add something to that effect in Kconfig ? > > > > I believe we want it to be enabled on distros in the long term. But right now it would > > be a bad idea until the off case (nohz_full= parameter empty) is carefully optimized. > > I'm currently working on that. > > > > Now for the unstable tsc, which is what it's about on the above code block, we need > > the tick to be there to leverage the sched clock madness. May be there could be some > > other solution that could work along full dynticks but for now we chose the easy path. > > > > Are broken TSCs that common? > > I just hit one apparently. http://paste.fedoraproject.org/25421/73907845/raw/ > That's a fairly recent Atom board, so I suspect it's not uncommon on that platform. > > > Also what is the preffered way to tell the distros that they shouldn't enable that option > > for now? Here is what we currently have in the tail of the related Kconfig help: > > > > This is implemented at the expense of some overhead in user <-> kernel > > transitions: syscalls, exceptions and interrupts. Even when it's > > dynamically off. > > "This feature is not ready to be deployed" ?
I can try this one. Or may be I should be more direct and put:
"This feature is not ready to be deployed on distros"
> > "This will taint the kernel if it decides it can't work" ? > > Dave >
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