On Fri, Apr 16, 2021 at 09:19:08PM +0900, Namhyung Kim wrote: > > Are you actually using mmap() to read? I had a proposal for FORMAT_GROUP > > like thing for mmap(), but I never implemented that (didn't get the > > enthousiatic response I thought it would). But yeah, there's nowhere > > near enough space in there for PERCPU. > > Recently there's a patch to do it with rdpmc which needs to mmap first. > > https://lore.kernel.org/lkml/20210414155412.3697605-1-r...@kernel.org/
Yeah, I'm not sure about that, I've not looked at it recently. The thing is though; for RDPMC to work, you *NEED* to be on the same CPU as the counter. The typical RDPMC use-case is self monitoring.
