[CRIU] [PATCH v3 1/6] p.haul: automatically detect dirty memory tracking

[Adrian Reber]

From: Adrian Reber <areber at redhat.com>

Use the newly added feature-check RPC to automatically detect
if pre-dumping should be enabled or disabled.

v2: rebased and using reworked FEATURE_CHECK interface

v3: rebased and using the 'features' protobuf message

Signed-off-by: Adrian Reber <areber at redhat.com>
---
 phaul/criu_api.py     |  5 +++++
 phaul/criu_req.py     | 11 ++++++++++-
 phaul/p_haul_iters.py | 18 ++++++++++++++++--
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/phaul/criu_api.py b/phaul/criu_api.py
index 81d22b1..9b2f369 100644
--- a/phaul/criu_api.py
+++ b/phaul/criu_api.py
@@ -25,6 +25,7 @@ class criu_conn:
 	def __init__(self, mem_sk):
 		self._iter = 0
 		self.verb = def_verb
+		self._track_mem = True
 		css = socket.socketpair(socket.AF_UNIX, socket.SOCK_SEQPACKET)
 		util.set_cloexec(css[1])
 		logging.info("`- Passing (ctl:%d, data:%d) pair to CRIU", css[0].fileno(), mem_sk.fileno())
@@ -55,6 +56,7 @@ class criu_conn:
 	def send_req(self, req):
 		req.opts.log_level = self.verb
 		req.opts.log_file = self.get_log_name(req.type)
+		req.opts.track_mem = self._track_mem
 		self._cs.send(req.SerializeToString())
 		self._iter += 1
 		self._last_req = req.type
@@ -72,6 +74,9 @@ class criu_conn:
 	def get_log_name(self, req_type):
 		return "criu_%s.%d.log" % (criu_req.get_name(req_type), self._iter)
 
+	def memory_tracking(self, value):
+		self._track_mem = value
+
 #
 # Helper to read CRIU-generated statistics
 #
diff --git a/phaul/criu_req.py b/phaul/criu_req.py
index 42225aa..d97d4cf 100644
--- a/phaul/criu_req.py
+++ b/phaul/criu_req.py
@@ -11,6 +11,7 @@ _names = {
 	pycriu.rpc.RESTORE: "restore",
 	pycriu.rpc.CPUINFO_DUMP: "cpuinfo-dump",
 	pycriu.rpc.CPUINFO_CHECK: "cpuinfo-check",
+	pycriu.rpc.FEATURE_CHECK: "feature-check",
 }
 
 def get_name(req_type):
@@ -37,7 +38,6 @@ def _make_common_dump_req(typ, pid, htype, img, connection, fs):
 	req = _make_req(typ, htype)
 	req.opts.pid = pid
 	req.opts.ps.fd = connection.mem_sk_fileno()
-	req.opts.track_mem = True
 
 	req.opts.images_dir_fd = img.image_dir_fd()
 	req.opts.work_dir_fd = img.work_dir_fd()
@@ -106,3 +106,12 @@ def make_restore_req(htype, img, nroot):
 		req.opts.root = nroot
 
 	return req
+
+def make_dirty_tracking_req(htype, img):
+	"""Check if dirty memory tracking is supported."""
+	req = _make_req(pycriu.rpc.FEATURE_CHECK, htype)
+	req.features.mem_track = True
+	req.keep_open = True
+	req.opts.images_dir_fd = img.work_dir_fd()
+	return req
+
diff --git a/phaul/p_haul_iters.py b/phaul/p_haul_iters.py
index 6050236..55dd819 100644
--- a/phaul/p_haul_iters.py
+++ b/phaul/p_haul_iters.py
@@ -86,9 +86,23 @@ class phaul_iter_worker:
 		self.fs.set_work_dir(self.img.work_dir())
 		self.fs.start_migration()
 
-		logging.info("Starting iterations")
+		logging.info("Checking for Dirty Tracking")
+		req = criu_req.make_dirty_tracking_req(self.htype, self.img)
+		resp = self.criu_connection.send_req(req)
 
-		while True:
+		pre_dump = False
+		if resp.success:
+			if resp.HasField('features'):
+				if resp.features.HasField('mem_track'):
+					if resp.features.mem_track:
+						logging.info("Starting iterations")
+						pre_dump = True
+			else:
+				self.criu_connection.memory_tracking(False)
+		else:
+			self.criu_connection.memory_tracking(False)
+
+		while pre_dump:
 			logging.info("* Iteration %d", iter_index)
 
 			self.target_host.start_iter()
-- 
1.8.3.1