On Thu, 6 Jun 2019 19:59:18 -0700 Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > On Thu, Jun 6, 2019 at 1:17 PM Matt Mullins <mmullins@xxxxxx> wrote: > > > > BPF_PROG_TYPE_RAW_TRACEPOINTs can be executed nested on the same CPU, as > > they do not increment bpf_prog_active while executing. > > > > This enables three levels of nesting, to support > > - a kprobe or raw tp or perf event, > > - another one of the above that irq context happens to call, and > > - another one in nmi context > > Can NMIs be nested? No, otherwise several things in the kernel will break. -- Steve