Re: [RFC 2/2] perf/core: change errno for sampling event not supported in hardware

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [RFC 2/2] perf/core: change errno for sampling event not supported in hardware
Date	2016-05-12 09:30 +0200
Message-ID	<rxTeh-WJ-5@gated-at.bofh.it> (permalink)
References	(3 earlier) <rwXal-1D1-73@gated-at.bofh.it> <rxI9b-6rJ-7@gated-at.bofh.it> <rxSid-7O-5@gated-at.bofh.it> <rxSBz-im-11@gated-at.bofh.it> <rxSLg-mB-17@gated-at.bofh.it>
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On Thu, May 12, 2016 at 12:24:25PM +0530, Vineet Gupta wrote:
> On Thursday 12 May 2016 12:12 PM, Peter Zijlstra wrote:
> >> Tried that and doesn't even compile. Reconfirms what Vince said, ENOTSUPP is not
> >> > exposed to userspace (being in include/linux and not include/uapi/linux)
> > Durr, so what does userspace see?
> 
> It sees the "value" of ENOTSUPP, i.e. 524 but there is no symbolic reference to it :-)

Ah.. which might be a hint that nobody is actually explicitly testing
for this and we might just get away with changing the ABI.

Vince, what say you; shall we try and get away with it? ;-)

Thread

[RFC 0/2] report perf sampling failing due to PMU lacking overflow intr support Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-05-09 11:40 +0200
  [RFC 2/2] perf/core: change errno for sampling event not supported in hardware Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-05-09 11:40 +0200
    Re: [RFC 2/2] perf/core: change errno for sampling event not supported  in hardware Vince Weaver <vincent.weaver@maine.edu> - 2016-05-09 16:00 +0200
      Re: [RFC 2/2] perf/core: change errno for sampling event not  supported in hardware Vineet Gupta <vgupta@synopsys.com> - 2016-05-09 19:30 +0200
        Re: [RFC 2/2] perf/core: change errno for sampling event not supported  in hardware Vince Weaver <vincent.weaver@maine.edu> - 2016-05-11 05:40 +0200
        Re: [RFC 2/2] perf/core: change errno for sampling event not  supported in hardware Peter Zijlstra <peterz@infradead.org> - 2016-05-11 21:40 +0200
          Re: [RFC 2/2] perf/core: change errno for sampling event not  supported in hardware Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-05-12 08:30 +0200
            Re: [RFC 2/2] perf/core: change errno for sampling event not  supported in hardware Peter Zijlstra <peterz@infradead.org> - 2016-05-12 08:50 +0200
              Re: [RFC 2/2] perf/core: change errno for sampling event not  supported in hardware Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-05-12 09:00 +0200
                Re: [RFC 2/2] perf/core: change errno for sampling event not  supported in hardware Peter Zijlstra <peterz@infradead.org> - 2016-05-12 09:30 +0200
                Re: [RFC 2/2] perf/core: change errno for sampling event not supported  in hardware Vince Weaver <vincent.weaver@maine.edu> - 2016-05-13 01:10 +0200
                Re: [RFC 2/2] perf/core: change errno for sampling event not  supported in hardware Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-05-13 10:40 +0200
                [PATCH-REBASED 0/2] report perf sampling failing due to PMU lacking overflow intr support Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-05-30 13:40 +0200
                [PATCH-REBASED 1/2] tools/perf: Handle EOPNOTSUPP for sampling events Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-05-30 13:40 +0200
                [PATCH-REBASED 2/2] perf/core: change errno for sampling event not supported in hardware Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-05-30 13:40 +0200

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