Re: [PATCH] perf, record: Add clockid parameter

[David Ahern]

On 3/27/15 11:20 AM, Peter Zijlstra wrote:
> > This is a new feature which means use_clockid on older kernels will fail. So
> > need to catch that and throw an error -- perhaps yet another probe function.
>
> How does that work? What do I grep to find an example? I figured if the
> kernel didn't support the syscall will fail and we'll terminate
> someplace.

Look at __perf_evsel__open(). In this case you probably do not want to 
fallback but tell the user the clock id option is not supported. The 
problem is deciphering the failure is due to the clock id versus all the 
other failure reasons.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/