Merge 'perftune.py: add support for VLAN interfaces' from Vladislav Z…

…olotarov

Add a long waited support for VLAN interfaces.

Tested manually with:
* bond interface on top of a physical device
* bond interface on top of another bond interface
* VLAN interface on top of a physical device
* VLAN interface on top of a bond interface

Closes scylladb#2333

* https://github.com/scylladb/seastar:
  scripts/perftune.py: add support for tweaking VLAN interfaces
  scripts/perftune.py: improve discovery of bond device slaves
  scripts/perftune.py: refactor __learn_slaves() function

scripts/perftune.py

@@ -575,10 +575,11 @@ def __init__(self, args):
 
  self.nics=args.nics
 
- self.__nic_is_bond_iface = self.__check_dev_is_bond_iface()
+ self.__nic_is_bond_iface = NetPerfTuner.__get_bond_ifaces()
+ self.__nic_is_vlan_iface = NetPerfTuner.__get_vlan_ifaces()
  self.__slaves = self.__learn_slaves()
 
- # check that self.nics contain a HW device or a bonding interface
+ # check that self.nics contain a HW device or a supported composite interface
  self.__check_nics()
 
  # Fetch IRQs related info
@@ -595,8 +596,8 @@ def tune(self):
  perftune_print("Setting a physical interface {}...".format(nic))
  self.__setup_one_hw_iface(nic)
  else:
- perftune_print("Setting {} bonding interface...".format(nic))
- self.__setup_bonding_iface(nic)
+ perftune_print(f"Setting a {nic} {'bond' if self.nic_is_bond_iface(nic) else 'VLAN'} interface...")
+ self.__setup_composite_iface(nic)
 
  # Increase the socket listen() backlog
  fwriteln_and_log('/proc/sys/net/core/somaxconn', '4096')
@@ -606,7 +607,13 @@ def tune(self):
  fwriteln_and_log('/proc/sys/net/ipv4/tcp_max_syn_backlog', '4096')
 
  def nic_is_bond_iface(self, nic):
- return self.__nic_is_bond_iface[nic]
+ return self.__nic_is_bond_iface.get(nic, False)
+
+ def nic_is_vlan_iface(self, nic):
+ return self.__nic_is_vlan_iface.get(nic, False)
+
+ def nic_is_composite_iface(self, nic):
+ return self.nic_is_bond_iface(nic) or self.nic_is_vlan_iface(nic)
 
  def nic_exists(self, nic):
  return self.__iface_exists(nic)
@@ -617,8 +624,8 @@ def nic_is_hw_iface(self, nic):
  def slaves(self, nic):
  """
  Returns an iterator for all slaves of the nic.
- If agrs.nic is not a bonding interface an attempt to use the returned iterator
- will immediately raise a StopIteration exception - use __dev_is_bond_iface() check to avoid this.
+ If agrs.nic is not a composite interface an attempt to use the returned iterator
+ will immediately raise a StopIteration exception - use nic_is_composite_iface() check to avoid this.
  """
  return iter(self.__slaves[nic])
 
@@ -646,7 +653,7 @@ def __check_nics(self):
  for nic in self.nics:
  if not self.nic_exists(nic):
  raise Exception("Device {} does not exist".format(nic))
- if not self.nic_is_hw_iface(nic) and not self.nic_is_bond_iface(nic):
+ if not self.nic_is_hw_iface(nic) and not self.nic_is_composite_iface(nic):
  raise Exception("Not supported virtual device {}".format(nic))
 
  def __get_irqs_one(self, iface):
@@ -732,22 +739,68 @@ def __iface_exists(self, iface):
  def __dev_is_hw_iface(self, iface):
  return os.path.exists("/sys/class/net/{}/device".format(iface))
 
- def __check_dev_is_bond_iface(self):
-  bond_dict = {}
+ @staticmethod
+ def __get_bond_ifaces():
  if not os.path.exists('/sys/class/net/bonding_masters'):
- for nic in self.nics:
- bond_dict[nic] = False
- #return False for every nic
- return bond_dict
- for nic in self.nics:
- bond_dict[nic] = any([re.search(nic, line) for line in open('/sys/class/net/bonding_masters', 'r').readlines()])
+ return {}
+
+ bond_dict = {}
+ for line in open('/sys/class/net/bonding_masters', 'r').readlines():
+ for nic in line.split():
+ bond_dict[nic] = True
+
  return bond_dict
 
+ @staticmethod
+ def __get_vlan_ifaces():
+ # Each VLAN interface is going to have a corresponding entry in /proc/net/vlan/ directory
+ return {pathlib.PurePath(pathlib.Path(f)).name: True
+ for f in filter(lambda vlan_name: vlan_name != "/proc/net/vlan/config", glob.glob("/proc/net/vlan/*"))}
+
+ def __learn_slaves_one(self, nic):
+ """
+ Learn underlying physical devices a given NIC
+
+ :param nic: An interface to search slaves for
+ """
+ slaves_list = set()
+ top_slaves_list = set()
+
+ if self.nic_is_bond_iface(nic):
+ top_slaves_list = set(itertools.chain.from_iterable(
+ [line.split() for line in open("/sys/class/net/{}/bonding/slaves".format(nic), 'r').readlines()]))
+ elif self.nic_is_vlan_iface(nic):
+ # VLAN interfaces have a symbolic link 'lower_<parent_interface_name>' under
+ # /sys/class/net/<VLAN interface name>.
+ #
+ # For example:
+ #
+ # lrwxrwxrwx 1 root root 0 Jul 5 18:38 lower_eno1 -> ../../../pci0000:00/0000:00:1f.6/net/eno1/
+ #
+ top_slaves_list = set([pathlib.PurePath(pathlib.Path(f).resolve()).name
+ for f in glob.glob(f"/sys/class/net/{nic}/lower_*")])
+
+ # Slaves can be themselves bond or VLAN devices: let's descend (DFS) all the way down to get physical devices.
+ # Bond slaves can't be VLAN interfaces but VLAN interface parent device can be a bond interface.
+ # Bond slaves can also be bonds.
+ # For simplicity let's not discriminate.
+ for s in top_slaves_list:
+ if self.nic_is_composite_iface(s):
+ slaves_list |= self.__learn_slaves_one(s)
+ else:
+ slaves_list.add(s)
+
+ return slaves_list
+
  def __learn_slaves(self):
+ """
+ Resolve underlying physical devices for interfaces we are requested to configure
+ """
  slaves_list_per_nic = {}
  for nic in self.nics:
- if self.nic_is_bond_iface(nic):
- slaves_list_per_nic[nic] = list(itertools.chain.from_iterable([line.split() for line in open("/sys/class/net/{}/bonding/slaves".format(nic), 'r').readlines()]))
+ current_slaves = self.__learn_slaves_one(nic)
+ if current_slaves:
+ slaves_list_per_nic[nic] = list(current_slaves)
 
  return slaves_list_per_nic
 
@@ -946,7 +999,7 @@ def __learn_irqs(self):
  """
  nic_irq_dict={}
  for nic in self.nics:
- if self.nic_is_bond_iface(nic):
+ if self.nic_is_composite_iface(nic):
  for slave in filter(self.__dev_is_hw_iface, self.slaves(nic)):
  nic_irq_dict[slave] = self.__learn_irqs_one(slave)
  else:
@@ -1038,7 +1091,11 @@ def __setup_one_hw_iface(self, iface):
  self.__setup_rps(iface, self.cpu_mask)
  self.__setup_xps(iface)
 
- def __setup_bonding_iface(self, nic):
+ def __setup_composite_iface(self, nic):
+ """
+ Set up the interface which is a bond or a VLAN interface
+ :param nic: name of a composite interface to set up
+ """
  for slave in self.slaves(nic):
  if self.__dev_is_hw_iface(slave):
  perftune_print("Setting up {}...".format(slave))