Re: [RFC PATCH v2 00/17] Core scheduling v2

From: Aaron Lu
Date: Tue May 07 2019 - 22:31:26 EST

On Mon, May 06, 2019 at 03:39:37PM -0400, Julien Desfossez wrote:
> On 29-Apr-2019 11:53:21 AM, Aaron Lu wrote:
> > This is what I have used to make sure no two unmatched tasks being
> > scheduled on the same core: (on top of v1, I thinks it's easier to just
> > show the diff instead of commenting on various places of the patches :-)
> We imported this fix in v2 and made some small changes and optimizations
> (with and without Peterâs fix from
> and in both cases, the performance problem where the core can end up

By 'core', do you mean a logical CPU(hyperthread) or the entire core?

> idle with tasks in its runqueues came back.

Assume you meant a hyperthread, then the question is: when a hyperthread
is idle with tasks sitting in its runqueue, do these tasks match with the
other hyperthread's rq->curr? If so, then it is a problem that need to
be addressed; if not, then this is due to the constraint imposed by the
mitigation of L1TF.