Re: [PATCH v4 1/5] nohz_full: add support for "cpu_isolated" mode

Andy Lutomirski
2015-07-13T20:41:21Z

On Mon, Jul 13, 2015 at 12:57 PM, Chris Metcalf <cmetcalf@ezchip.com> wrote:
> The existing nohz_full mode makes tradeoffs to minimize userspace
> interruptions while still attempting to avoid overheads in the
> kernel entry/exit path, to provide 100% kernel semantics, etc.
>
> However, some applications require a stronger commitment from the
> kernel to avoid interruptions, in particular userspace device
> driver style applications, such as high-speed networking code.
>
> This change introduces a framework to allow applications to elect
> to have the stronger semantics as needed, specifying
> prctl(PR_SET_CPU_ISOLATED, PR_CPU_ISOLATED_ENABLE) to do so.
> Subsequent commits will add additional flags and additional
> semantics.

I thought the general consensus was that this should be the default
behavior and that any associated bugs should be fixed.

--Andy