[CRIU] [PATCH v3 4/6] p.haul: add option to enable/disable pre-dumps

[Adrian Reber]

On Fri, Oct 09, 2015 at 08:24:42PM +0300, Pavel Emelyanov wrote:
> On 10/09/2015 07:53 PM, Adrian Reber wrote:
> > On Fri, Oct 09, 2015 at 06:40:47PM +0300, Pavel Emelyanov wrote:
> >> On 10/08/2015 05:06 PM, Adrian Reber wrote:
> >>> From: Adrian Reber <areber at redhat.com>
> >>>
> >>> Although p.haul can now auto-detect if the used criu supports
> >>> memory tracking this adds a command-line option to force
> >>> pre-dumping on or off:
> >>>
> >>>   --no-pre-dump        Force disable pre-dumps
> >>>   --pre-dump           Force enable pre-dumps
> >>>
> >>> Signed-off-by: Adrian Reber <areber at redhat.com>
> >>> ---
> >>>  p.haul                | 12 ++++++++++++
> >>>  phaul/p_haul_iters.py | 18 ++++++++++++++----
> >>>  2 files changed, 26 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/p.haul b/p.haul
> >>> index e807c8f..6239709 100755
> >>> --- a/p.haul
> >>> +++ b/p.haul
> >>> @@ -36,6 +36,18 @@ parser.add_argument("--log-file", help="Write logging messages to specified file
> >>>  parser.add_argument("-j", "--shell-job",help ="Allow migration of shell jobs",
> >>>  		    default=False, action='store_true')
> >>>  
> >>> +
> >>> +parser.add_argument('--no-pre-dump', dest='pre_dump', action='store_const',
> >>> +		    const=1, help='Force disable pre-dumps')
> >>> +parser.add_argument('--pre-dump', dest='pre_dump', action='store_const',
> >>> +		    const=2, help='Force enable pre-dumps')
> >>> +
> >>> +# If pre_dump is 0 then pre-dump autodetection should be used.
> >>> +# If it is 1 or 2 it should be either enabled or disabled no
> >>> +# matter if the kernel supports dirty page tracking or not.
> >>> +
> >>> +parser.set_defaults(pre_dump = 0)
> >>> +
> >>>  args = parser.parse_args()
> >>>  
> >>>  # Configure logging
> >>> diff --git a/phaul/p_haul_iters.py b/phaul/p_haul_iters.py
> >>> index ba96de3..96458b8 100644
> >>> --- a/phaul/p_haul_iters.py
> >>> +++ b/phaul/p_haul_iters.py
> >>> @@ -42,6 +42,9 @@ class phaul_iter_worker:
> >>>  		self.pid = self.htype.root_task_pid()
> >>>  		self.fs.set_target_host(host[0])
> >>>  
> >>> +		# pre_dump 0 means auto-detection
> >>> +		self.pre_dump = 0
> >>> +
> >>>  		logging.info("Setting up remote")
> >>>  		self.target_host.setup(p_type)
> >>>  
> >>> @@ -55,6 +58,7 @@ class phaul_iter_worker:
> >>>  		self.img.set_options(opts)
> >>>  		self.htype.set_options(opts)
> >>>  		self.__force = opts["force"]
> >>> +		self.pre_dump = opts["pre_dump"]
> >>>  
> >>>  	def validate_cpu(self):
> >>>  		logging.info("Checking CPU compatibility")
> >>> @@ -87,11 +91,17 @@ class phaul_iter_worker:
> >>>  		self.fs.set_work_dir(self.img.work_dir())
> >>>  		self.fs.start_migration()
> >>>  
> >>> -		logging.info("Checking for Dirty Tracking")
> >>> -		req = criu_req.make_dirty_tracking_req(self.htype, self.img)
> >>> -		resp = self.criu_connection.send_req(req)
> >>> +		if self.pre_dump == 0:
> >>> +			# pre-dump auto-detection
> >>> +			logging.info("Checking for Dirty Tracking")
> >>> +			req = criu_req.make_dirty_tracking_req(self.htype, self.img)
> >>> +			resp = self.criu_connection.send_req(req)
> >>> +			pre_dump = resp.success
> >>> +		elif self.pre_dump == 1:
> >>> +			pre_dump = False
> >>> +		else:
> >>> +			pre_dump = True
> >>>  
> >>> -		pre_dump = False
> >>>  		if resp.success:
> >>
> >> The resp will be "uninitialized" in case self.pre_dump != 0 and you
> >> set up the pre_dump variable to True/False by hands.
> > 
> > The follow-up patches I posted should fix this. Having rebased this code
> > a few times I am not 100% sure the intermediate patches provide an error
> > free implementation. At the end I have only tested the whole patchset.
> 
> Ah, I see.
> 
> > Should I respin starting from this patch or is it good enough if the
> > code is correct after all my patches have been applied.
> 
> Can you please re-shuffle the patches, so that there are two patches -- one
> with auto-detection and the other one adding "forced" option that ignores
> the automatic detection?

The patches are already split up like this. Auto-detection was
implemented in the first patch of the series. This patch (4/6) adds the
command-line option to force pre-dumps on or off.

5/6 adds the possibility to use an older version of criu which does not
have the feature-check interface (like 1.7 and older) and patch 6/6
moves the auto-detection to its own function as it has become large
enough to be a separate function.

		Adrian