Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends

From: Peter Zijlstra
Date: Thu Sep 24 2020 - 09:59:54 EST


On Thu, Sep 24, 2020 at 09:51:38AM -0400, Steven Rostedt wrote:

> > It turns out, that getting selected for pull-balance is exactly that
> > condition, and clearly a migrate_disable() task cannot be pulled, but we
> > can use that signal to try and pull away the running task that's in the
> > way.
>
> Unless of course that running task is in a migrate disable section
> itself ;-)

See my ramblings here:

https://lkml.kernel.org/r/20200924082717.GA1362448@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

My plan was to have the migrate_enable() of the running task trigger the
migration in that case.