Re: [PATCH RFC v2 08/15] bpf, x86: Maintain Tasks RCU trampoline nesting in the BPF trampoline

[David Laight]

On Sat, 12 Sep 2026 11:03:34 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:

> In the old kernels, yes, we have current->trc_reader_nesting++.
> In the newer kernels, Tasks Trace RCU is instead implemented in terms
> of SRCU-fast, which instead increments per-CPU counters.  Which among
> other thins is a bit faster and does not need to hook into the scheduler.

Isn't that rather architecture dependant?
It is fine on x86, but on arm incrementing a per-cpu variable is
significantly expensive.

David