On Thu, Jun 01, 2017 at 02:17:21PM +0200, Peter Zijlstra wrote: > On Thu, Jun 01, 2017 at 06:58:20AM -0500, Josh Poimboeuf wrote: > > > Being able to generate more optimal code in the hottest code paths of the kernel > > > is the _real_, primary upstream kernel benefit of a different debuginfo method - > > > which has to be weighed against the pain of introducing a new unwinder. But this > > > submission does not talk about that aspect at all, which should be fixed I think. > > > > Actually I devoted an entire one-sentence paragraph to performance in > > the documentation: > > > > The simpler debuginfo format also enables the unwinder to be relatively > > fast, which is important for perf and lockdep. > > > > But I'll try to highlight that a little more. > > That's relative to a DWARF unwinder. Yes. > It doesn't appear to be possible to get anywhere near a frame-pointer > unwinder due to having to do this log(n) lookup for every single > frame. Hm, is there something faster, yet not substantially bigger? Hash? Trie? -- Josh -- 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
