Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [RFC 0/6] perf tools: Add perf_evlist errno | Date | Mon, 02 Dec 2013 17:19:18 +0900 |
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Hi Jiri,
On Fri, 29 Nov 2013 12:45:04 +0100, Jiri Olsa wrote: > hi, > Andi reported wrong error message for :S modifier > on kernel without event ID ioctl support. > > The reason was that the ioctl failed, but the error was > printed like the mmap would: > > $ perf.old record -e '{cycles,cache-misses}:S' ls > failed to mmap with 25 (Inappropriate ioctl for device) > ls: Terminated
I see same confusing error message..
> > I experimentally added sort of 'libc errno' interface for > perf_evlist to be able to get proper error message, like: > > $ perf record -e '{cycles,cache-misses}:S' ls > Cannot read event group on this kernel. > Please consider kernel update (v3.12+). > ls: Terminated > > I'm not sure about this approach. Maybe it'd be better be more > global..? So before throwing this out, sending it as RFC ;-)
I like it. :) We still need to improve this user-visible error handling.
But what you mean by 'more global'? I think the evlist APIs are pretty global alreay. And we have same error handling in perf_target code too.
But I think it'd be better making it thread-safe even though it's not needed for now. The code is growing really fast.. ;-)
Thanks, Namhyung
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