Re: [PATCH] sched/fair: Prefer idle CPU to cache affinity

[Srikar Dronamraju]

* Peter Zijlstra <peterz@xxxxxxxxxxxxx> [2021-03-02 10:10:32]:

> On Tue, Mar 02, 2021 at 01:09:46PM +0530, Srikar Dronamraju wrote:
> > > Oh, could be, I didn't grep :/ We could have core code keep track of the
> > > smt count I suppose.
> > 
> > Could we use cpumask_weight(cpu_smt_mask(this_cpu)) instead?
> 
> cpumask_weight() is potentially super expensive. With CPUMASK_OFFSTACK
> you get at least one more cache miss and then the bitmap might be really
> long.
> 
> Best to compute the results once and use it later.

Oh okay .. Noted.

-- 
Thanks and Regards
Srikar Dronamraju