Re: [RFC PATCH] Remove redundant sched_numa_balancing check.

[Imran Khan]

On 18/1/21 9:57 pm, Mel Gorman wrote:
> On Mon, Jan 18, 2021 at 09:32:18PM +1100, Imran Khan wrote:
> > task_numa_fault is invoked from do_numa_page/do_huge_pmd_numa_page,
> > for task_numa_work induced memory faults. task_numa_work is scheduled
> > from task_tick_numa which is invoked only if sched_numa_balancing
> > is true.
> >
> > So task_numa_fault will not get invoked if sched_numa_balancing is
> > false and hence we can avoid checking it again in task_numa_fault.
> >
> > Signed-off-by: Imran Khan <imran.f.khan@xxxxxxxxxx>
>
> If NUMA balancing is disabled at runtime, there may still be PTEs that
> are marked for NUMA balancing. While these still get handled at fault,
> there is no point tracking the fault information in task_numa_fault and
> this function can still get called after sched_numa_balancing is
> disabled.

Okay, understood. Thanks for clarifying.