[CRIU] [PATCH] test/zdtm: do not allow running with --lazy-pages on kernel without uffd

[Mike Rapoport]

On Mon, Jul 10, 2017 at 11:32:09AM +0300, Pavel Emelyanov wrote:
> On 07/09/2017 09:12 AM, Mike Rapoport wrote:
> > Raise an exception for kernels that do not have userfaultfd. For the
> > kernels that have userfaultfd but do not provide non-cooperative events
> > (4.3 - 4.10) warn about incomplete feature.
> > 
> > Fixes: #363
> > 
> > Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
> > ---
> >  test/zdtm.py | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> > 
> > diff --git a/test/zdtm.py b/test/zdtm.py
> > index 2ee76cd..e6d2701 100755
> > --- a/test/zdtm.py
> > +++ b/test/zdtm.py
> > @@ -1767,6 +1767,16 @@ def run_tests(opts):
> >  		if subprocess.Popen(["ip", "netns", "exec", "zdtm_netns", "ip", "link", "set", "up", "dev", "lo"]).wait():
> >  			raise Exception("ip link set up dev lo")
> >  
> > +	if opts['lazy_pages'] or opts['remote_lazy_pages']:
> > +		check = subprocess.Popen([criu_bin, "check", "--feature", "lazy_pages"], stderr = subprocess.PIPE)
> 
> There's a helper for that:
> 
>         if opts['pre'] or opts['snaps']:
>                 if not criu.check("mem_dirty_track"):
>                         print "Tracking memory is not available"
>                         return
> 
> so you can do it with
> 
> 	if not criu.check("lazy_pages"):
> 		<bail-out>

It will return 1 even if uffd is present, but it still does not have
non-cooperative events. For instance, in travis ;-)
 
> > +		ret = check.wait()
> > +		err = ''.join(check.stderr.readlines())
> > +		if ret:
> > +			if "UFFD is not supported" in err:
> > +				raise Exception("UFFD is not supported, cannot run with --lazy-pages")
> > +			# Most test will work with 4.3 - 4.10
> > +			print "WARNING: UFFD is missing essentail features"
> > +
> >  	l = launcher(opts, len(torun))
> >  	try:
> >  		for t in torun:
> > 
> 

-- 
Sincerely yours,
Mike.