Messages in this thread | | | Date | Fri, 31 Oct 2014 12:28:24 +0000 | From | Matt Fleming <> | Subject | Re: [RFD] perf syscall error handling |
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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.
-- Matt Fleming, Intel Open Source Technology Center
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