Richard Biener via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> On Fri, Jun 30, 2023 at 7:28 AM Eugene Rozenfeld via Gcc-patches > <gcc-patches@gcc.gnu.org> wrote: >> >> When we collect just user events for autofdo with lbr we get some events >> where branch >> sources are kernel addresses and branch targets are user addresses. Without >> kernel MMAP >> events create_gcov can't make sense of kernel addresses. Currently >> create_gcov fails if >> it can't map at least 95% of events. We sometimes get below this threshold >> with just >> user events. The change is to collect both user events and kernel events. > > Does this require elevated privileges? Can we instead "fix" create_gcov here? Right, requiring privileges for this is going to be a no-go for a lot of builders. In a distro context, for example, it means we can't consider autofdo at all.
