On Thu, Jul 13, 2017 at 05:03:00AM +0200, Mike Galbraith wrote: > On Wed, 2017-07-12 at 15:30 -0700, Andi Kleen wrote: > > Josh Poimboeuf <jpoimboe@xxxxxxxxxx> writes: > > > > > > The ORC data format does have a few downsides compared to DWARF. The > > > ORC unwind tables take up ~1MB more memory than DWARF eh_frame tables. > > > > > Can we have an option to just use dwarf instead? For people > > who don't want to waste a MB+ to solve a problem that doesn't > > exist (as proven by many years of opensuse kernel experience) > > Sure the dwarf unwinder works well for crashes, but at the price of > demolishing ftrace/perf utility. You mean the unwind performance? That's a valid concern, but neither ORC nor dwarf are likely to address it. However most usages of ftrace/perf shouldn't be that depending on unwind performance -- just lower the frequency of your events. The only possible win is if the win from not using FP code is significant enough. On the x86 side the only modern CPUs that should really care about this are Atoms. -Andi -- 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
