On Wed, Jul 28, 2021 at 11:12 AM Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote: > > Are the percpu atomics you have in mind different from what is found in > Documentation/core-api/this_cpu_ops.rst ? > > Namely this_cpu_add_return(pcp, val) in this case. Nope. Those are only "CPU-atomic", ie atomic wrt interrupts etc. The RCU code wants SMP-atomic, and it's mainly that we *could* do the addressing more efficiently. Linus