mir/ovs
2
0
Fork 0
mirror of https://github.com/openvswitch/ovs synced 2025-08-22 09:58:01 +00:00
Code Issues Releases Wiki Activity

utilities: usdt-scripts: Retry on dp cache miss.

Browse Source 
If the dp cache request misses, retry but only a couple of times so we
don't overload the system and only if we're not running on an externally
provided cache.

Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
This commit is contained in:
Adrián Moreno 2025-03-31 21:27:05 +02:00 committed by Eelco Chaudron
parent 340c574e46
commit ae6b778abb
1 changed files with 34 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
utilities/usdt-scripts/usdt_lib.py
View File

@ -19,43 +19,60 @@ import subprocess
class DpPortMapping: class DpPortMapping:
"""Class used to retrieve and cache datapath port numbers to port names.""" """Class used to retrieve and cache datapath port numbers to port names."""
MAX_REQUESTS = 2
def __init__(self): def __init__(self):
self.cache_map = None self.cache_map = None
self.n_requests = 0
def get_map(self): def get_map(self):
"""Get the cache map.""" """Get the cache map."""
if not self.cache_map: self._get_mapping()
self._get_mapping()
return self.cache_map return self.cache_map
def set_map(self, cache_map): def set_map(self, cache_map):
"""Override the internal cache map.""" """Override the internal cache map."""
self.cache_map = cache_map self.cache_map = cache_map
self.n_requests = self.MAX_REQUESTS
def _retry(self, func):
self._get_mapping()
result = func(self.cache_map)
if not result:
self._get_mapping(refresh=True)
return func(self.cache_map)
return result
def get_port_name(self, dp, port_no): def get_port_name(self, dp, port_no):
"""Get the port name from a port number.""" """Get the port name from a port number."""
if self.cache_map is None: def _get_port_name(cache_map):
self._get_mapping() if not cache_map.get(dp):
return None
for name, num in cache_map[dp].items():
if num == port_no:
return name
if not self.cache_map.get(dp): return self._retry(_get_port_name)
return None
for name, num in self.cache_map[dp].items():
if num == port_no:
return name
return None
def get_port_number(self, dp, port): def get_port_number(self, dp, port):
"""Get the port number from a port name.""" """Get the port number from a port name."""
if self.cache_map is None: def _get_port_number(cache_map):
self._get_mapping() return cache_map.get(dp, {}).get(port, None)
return self.cache_map.get(dp, {}).get(port, None) return self._retry(_get_port_number)
def _get_mapping(self): def _get_mapping(self, refresh=False):
"""Get the datapath port mapping from the running OVS.""" """Get the datapath port mapping from the running OVS."""
if self.n_requests >= self.MAX_REQUESTS \
or (self.cache_map and not refresh):
return
self.n_requests += 1
try: try:
output = subprocess.check_output( output = subprocess.check_output(
["ovs-appctl", "dpctl/show"], encoding="utf8" ["ovs-appctl", "dpctl/show"], encoding="utf8"
@ -82,3 +99,4 @@ class DpPortMapping:
self.cache_map[current_dp] = { self.cache_map[current_dp] = {
match.group(2): int(match.group(1)) match.group(2): int(match.group(1))
} }