Hi, On Fri, Oct 31, 2014 at 1:28 PM, Matt Fleming <m...@console-pimps.org> wrote: > On Fri, 31 Oct, at 10:27:13AM, Ingo Molnar wrote: >> >> - user-space gets back the regular errno (-EOPNOTSUPP or -ENOSYS >> or -EINVAL, etc.) and a string. Strings are really the most >> helpful information, because tools can just print that. They >> can also match on specific strings and programmatically react >> to them if they want to: we can promise to not arbitrarily >> change error strings once they are introduced. (but even if >> they change, user-space can still print them out.) > > I guess we'd run into a problem if userspace doesn't want to just print > the kernel string but instead wants to parse it in some fashion. > > That may or may not be a problem in practice, Vince can probably comment > on that. I'm just thinking along the lines of making the perf syscall > interface as useful as possible for tools other than tools/perf. > Maybe I missed something in the earlier thread, but I am trying to understand why perf_event_open() would need such extended error retrieval system when no other syscall does.
In any case, I would go with Ingo's proposal. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
