* Frederic Weisbecker <fweis...@gmail.com> wrote:
> > - Please outline how the current TODO entries affect upstream
> > mergability. Does it reduce the 'full'-ness of this dynticks mode?
> > Outright buggy behavior? Other trade-offs?
>
> Mostly this is about upstream features that won't be working with the current
> state of the art: enqueuing a posix cpu timer on a nohz CPU may result in it
> being
> ignored by the target due to the lack of ticking until expiration, perf
> events may
> not be round-robined, etc... I'll make sure to document all these items.
So it's "buggy behavior of existing features" it appears?
It would be really useful to add some sort of 'make it safe easily' mechanism:
- if a posix timer is enqueued on a CPU, then the CPU should have a timer
ticking
- if perf events are active on a CPU, then it should have a timer ticking
this would make it mergable, as most of the time systems don't have any of
these
facilities active. Plus this dynticks-off mechanism would also allow us to
cover any
other (still unknown) facility that regresses. So it would be nice to have that
option.
Later on we could gradually eliminate these limitations. It would also be
apparent
where they are, just from grepping the source.
If that's done, and if it tests fine for a few weeks then this could be v3.10
material IMO.
Thanks,
Ingo
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