[Piglit] [PATCH] dmesg.py: Make timestamp check slightly smarter

[Ben Widawsky]

On Mon, Aug 11, 2014 at 11:57:43AM -0700, Dylan Baker wrote:
> On Thursday, August 07, 2014 04:16:39 PM Ben Widawsky wrote:
> > If users wish to clear their dmesg before a piglit run, the current code
> > will emit a warning. It is possible to query the information about the
> > running kernel, and most distros do package that, so default to that.
> > The live kernel config is more future proof than regex parsing of the
> > timestamp (although I'd be shocked if either ever stopped working), and
> > it works for the empty dmesg case.
> > ---
> >  framework/dmesg.py | 19 +++++++++++++++++--
> >  1 file changed, 17 insertions(+), 2 deletions(-)
> > 
> > diff --git a/framework/dmesg.py b/framework/dmesg.py
> > index 1a8faa2..54f7119 100644
> > --- a/framework/dmesg.py
> > +++ b/framework/dmesg.py
> > @@ -40,6 +40,7 @@ import sys
> >  import subprocess
> >  import warnings
> >  import abc
> > +import gzip
> > 
> >  __all__ = [
> >      'BaseDmesg',
> > @@ -163,8 +164,22 @@ class LinuxDmesg(BaseDmesg):
> >          # on Linux because each entry is guaranteed unique by timestamps.
> >          self._last_message = None
> >          super(LinuxDmesg, self).__init__()
> > -
> > -        if not self._last_message:
> > +        printk_has_timestamps = False
> > +
> > +        # First check to see if we can find the live kernel config.
> > +        try:
> > +            f = gzip.open("/proc/config.gz", 'r')
> > +            for line in f:
> > +                if line.startswith("CONFIG_PRINTK_TIME=y"):
> > +                    printk_has_timestamps = True
> > +                    break
> 
> could you just return here instead of using the flag? It seems like you could.
> 

Yeah. Looks that way to me as well. I did a quick hack from the original
'finally' (which we talked about why that won't work). I'll get around
to a respin eventually.

> > +            f.close()
> > +        except Exception:
> > +            pass
> > +
> > +        if printk_has_timestamps:
> > +            return
> > +        elif not self._last_message:
> >              # We need to ensure that there is something in dmesg to check
> >              # timestamps.
> >              warnings.warn("Cannot check dmesg for timestamp support. If you
> > "
> 



-- 
Ben Widawsky, Intel Open Source Technology Center