Messages in this thread | | | Date | Mon, 3 Nov 2014 15:00:59 -0200 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [RFD] perf syscall error handling |
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Em Mon, Nov 03, 2014 at 05:50:19PM +0100, Peter Zijlstra escreveu: > On Mon, Nov 03, 2014 at 02:25:48PM -0200, Arnaldo Carvalho de Melo wrote:
> > The way that peterz suggested, i.e. returning information about which > > perf_event_attr and which of the parameters was invalid/had issues could > > help with fallbacking/capability querying, i.e. tooling may want to use > > some features if available automagically, fallbacking to something else > > when that fails.
> > We already do that to some degree in various cases, but for some if the > > only way that becomes available to disambiguate some EINVAL return is a > > string, code will start having strcmps :-\
> OK, so how about we do both, the offset+mask for the tools and the > string for the humans?
Yeah, tooling tries to provide the best it can with the offset+mask, and if doesn't manage to do anything smart with it, just show the string and hope that helps the user to figure out what is happening.
- Arnaldo
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