On Mon, Jun 19, 2017 at 08:21:51AM -0700, Andi Kleen wrote: > > I was trying to get a feel for how that compares to what we can do > > today. For other reasons (e.g. fd exhaustion), opening NR_CPUS * n > > You just have to increase the fd limit. The 1024 fd default is just > archaic for larger systems and doesn't really make any sense because > it only controls very small amounts of kernel memory. > > > events might not be a great idea on systems with a huge number of CPUs. > > We might want a heuristic in the perf tool regardless. > > But there's no alternative: we have to measure all CPUs with all events.
You can measure the process on all CPUs by using 1 event without a CPU filter, rather than NR_CPUS events. Thanks, Mark.
