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

2016-05-09 Thread Vince Weaver
On Mon, 9 May 2016, Vineet Gupta wrote: > This allows userspace to identify this case specifically from the > catch all error msg it prints currently. > > This is an ABI change An ABI change which will probably break things. The original change from ENODEV to ENOTSUPP managed to break things a

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

2016-05-10 Thread Vince Weaver
On Mon, 9 May 2016, Vineet Gupta wrote: > On Monday 09 May 2016 07:24 PM, Vince Weaver wrote: > > On Mon, 9 May 2016, Vineet Gupta wrote: > > > >> This allows userspace to identify this case specifically from the > >> catch all error msg it prints currently

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

2016-05-12 Thread Vince Weaver
On Thu, 12 May 2016, Peter Zijlstra wrote: > 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? ;-) It's probably worth trying. The only other time anyone