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

On Mon, Jul 13, 2015 at 12:57 PM, Chris Metcalf [off-list ref] 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