On Tue, 7 Aug 2018 20:53:54 -0700 Joel Fernandes <joe...@google.com> wrote:
> > When I talked to Paul few months ago about SRCU from NMI context, he > > mentioned the per-cpu memory operations during srcu_read_lock can be > > NMI interrupted, that's why we added that warning. > > So I looked more closely, __srcu_read_lock on 2 different handles may > still be doing a this_cpu_inc on the same location.. > (sp->sda->srcu_lock_count). :-( > > Paul any ideas on how to solve this? > > It does start to seem like a show stopper :-( What's wrong with a this_cpu_inc()? It's atomic for the CPU. Although it wont be atomic for the capture of the idx. But I also don't see interrupts being disabled, thus an NMI is no different than any interrupt doing the same thing, right? -- Steve
