On Wednesday 27 April 2016 08:43 PM, Lada Trimasova wrote: > On Tue, 2016-04-26 at 12:42 +0000, Vineet Gupta wrote: > > On Friday 22 April 2016 06:56 PM, Lada Trimasova wrote: > I think what we have now is sufficient - but u seem to want a prettier > failure output. > > Anyhow, this print is coming from util/evsel.c: perf_evsel__open_strerror() > At the very least you want another entry in switch case for ENOTSUPP and then > check if event was sampling one ( > evsel->attr.sample_period) - use that as a hint for saying sampling events not > supported. > > > > > ENOTSUPP is not visible for user programs. So it's impossible to add this > entry > > to mentioned switch. > > I think that there is no good way to make error message more understandable > > without breaking existing api.
I meant EOPNOTSUPP. Any errno value has to be visible to user programs otherwise there is no point defining it.
