Re: [PATCH] perf tools: get version from uname(2), not /proc

[Adrian Hunter <adrian.hunter@intel.com>]

On 07/10/15 20:11, Matt Mullins wrote:
> On Wed, Oct 07, 2015 at 11:19:17AM +0300, Adrian Hunter wrote:
>> On 07/10/15 11:18, Jiri Olsa wrote:
>>> On Tue, Oct 06, 2015 at 03:53:14PM -0700, Matt Mullins wrote:
>>>> Tools in kmod (e.g. modprobe) compose the module path from the release
>>>> from uname(2).  Because we use the UNAME26 personality, we need perf to
>>>> find modules located at the same path as the system tools.
>>>
>>> I guess it's easy to google this up, but could you
>>> please state in the changelog what's the difference
>>> between the current version and the UNAME26 one?
>>>
>>> Also state (and check) this change wouldn't affect other
>>> parts of the code that use this version (if there's any).
> 
> This is the only caller of get_kernel_version.
> 
>> Isn't the machine root dir for guests? uname() won't work for them.
> 
> Aye, this would break --guestmount.  Would it make sense to use uname()
> iff root_dir is the empty string, or is that too much special-casing for
> good taste?

There is machine__is_host(), but what about /proc/sys/kernel/osrelease or
does that have the same problem?