On 2017-07-12 17:40:45 -0500, Josh Poimboeuf wrote: > On Wed, Jul 12, 2017 at 03:36:05PM -0700, Andres Freund wrote: > > Hi, > > > > On 2017-07-12 17:32:25 -0500, Josh Poimboeuf wrote: > > > If you want perf to be able to use ORC instead of DWARF for user space > > > binaries, that's not currently possible, though I don't see any > > > technical blockers for doing so. Perf would need to be taught to read > > > ORC data. > > > > Right, that's what I was hoping for. > > > > > > > And I think it should be possible to convert DWARF to ORC, assuming the > > > DWARF data is trusted. We could probably add an objtool subcommand for > > > that. > > > > That'd be pretty helpful. > > Can I ask why? Is DWARF too slow, or is it something else? Both. Dwarf is really slow and uses a lot of space - on a bigger machine it's often nearly unusable. Secondly dwarf isn't available for BPF based stuff, IIUC because the kernel has to create a full backtrace there (rather than saving enough data that userland can do so). Which wasn't "allowed" to be done in-kernel w/ dwarf, just fp so far. - Andres -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
