Re: linux-next: manual merge of the rcu tree with the ftrace tree

[Paul E. McKenney]

On Tue, Nov 18, 2025 at 08:35:08AM +0100, Sebastian Andrzej Siewior wrote:
> On 2025-11-14 10:31:45 [-0800], Yonghong Song wrote:
> > > I believe that migration needs to be disabled at this point, but I am
> > > again adding Yonghong on CC for his perspective.
> > 
> > Yes, migration needs to be disabled for rt kernel in order to let
> > bpf program running properly.
> 
> Why is disabling migration special in regard to RT kernels vs !RT?
> Why do we need to disable migration given that bpf_prog_run_array()
> already does that? Is there a different entry point? 
> My point why is it required to disable migration on trace-point entry
> for BPF given that the BPF-entry already does so.

When I tried doing without that disabling some weeks back, it broke.

Maybe things have changed since, but I must defer to Yonghong &c.

							Thanx, Paul