On Thu, Jun 15, 2017 at 12:35:39PM -0700, Stephane Eranian wrote: > On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen <a...@linux.intel.com> wrote: > > On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: > >> On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen <a...@linux.intel.com> wrote: > >> > On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: > >> >> This patchs adds a new sample record type called > >> >> PERF_SAMPLE_SKID_IP. The goal is to record > >> >> the unmodified interrupted instruction pointer (IP) as seen by > >> >> the kernel and reflected in the machine state. > >> > > >> > Patches look reasonable for me. > >> > > >> > If you only cared about branches it would be more natural to model > >> > it like a 1 entry LBR. That would make a lot more tooling work > >> > automatically. > >> > > >> You'd still have to modify tooling to present correct column headers. > > > > Why? It's from/to? > > > Ah, yes you are right, but it is not clear to me how you would specify > this cleanly with the interface. > Especially in the case where this could be used for non-branch instructions.
Generally the skid ip is only interesting for instructions that have some kind of control flow change, or an exception/interrupt. So if it's interesting the headers would be correct. Actually it's even correct for non control flow change, because the IP moves from "FROM" to "TO" ... -Andi
