do not log messages about slices that receive default coresched reservations

diff --git a/coresched.py b/coresched.py
index dd6dd04..0802ad8 100644 (file)
--- a/coresched.py
+++ b/coresched.py
@@ -21,8 +21,32 @@ class CoreSched:
         One core is always left unreserved for system slices.
     """
 
-    def __init__(self):
+    def __init__(self, cgroup_var_name="cpuset.cpus", slice_attr_name="cpu_cores"):
         self.cpus = []
+        self.cgroup_var_name = cgroup_var_name
+        self.slice_attr_name = slice_attr_name
+
+    def get_cgroup_var(self, name):
+        """ decode cpuset.cpus or cpuset.mems into a list of units that can
+            be reserved.
+        """
+
+        data = open("/dev/cgroup/" + name).readline().strip()
+
+        units = []
+
+        # cpuset.cpus could be something as arbitrary as:
+        #    0,1,2-3,4,5-6
+        # deal with commas and ranges
+        for part in data.split(","):
+            unitRange = part.split("-")
+            if len(unitRange) == 1:
+                unitRange = (unitRange[0], unitRange[0])
+            for i in range(int(unitRange[0]), int(unitRange[1])+1):
+                if not i in units:
+                    units.append(i)
+
+        return units
 
     def get_cpus(self):
         """ return a list of available cpu identifiers: [0,1,2,3...]
@@ -33,20 +57,9 @@ class CoreSched:
         if self.cpus!=[]:
             return self.cpus
 
-        cpuset_cpus = open("/dev/cgroup/cpuset.cpus").readline().strip()
+        self.cpus = self.get_cgroup_var(self.cgroup_var_name)
 
-        # cpuset.cpus could be something as arbitrary as:
-        #    0,1,2-3,4,5-6
-        # deal with commas and ranges
-        for part in cpuset_cpus.split(","):
-            cpuRange = part.split("-")
-            if len(cpuRange) == 1:
-                cpuRange = (cpuRange[0], cpuRange[0])
-            for i in range(int(cpuRange[0]), int(cpuRange[1])+1):
-                if not i in self.cpus:
-                    self.cpus.append(i)
-
-            return self.cpus
+        return self.cpus
 
     def get_cgroups (self):
         """ return a list of cgroups
@@ -84,48 +97,50 @@ class CoreSched:
                     rec['_rspec'] is the effective rspec
         """
 
-        logger.log("CoreSched: adjusting cores")
-
         cpus = self.get_cpus()[:]
 
+        logger.log("CoreSched (" + self.cgroup_var_name + "): available units: " + str(cpus))
+
         reservations = {}
 
         # allocate the cores to the slivers that have them reserved
         for name, rec in slivers.iteritems():
             rspec = rec["_rspec"]
-            cores = rspec.get("cpu_cores", 0)
+            cores = rspec.get(self.slice_attr_name, 0)
             (cores, bestEffort) = self.decodeCoreSpec(cores)
 
             while (cores>0):
                 # one cpu core reserved for best effort and system slices
                 if len(cpus)<=1:
-                    logger.log("CoreSched: ran out of cpu cores while scheduling: " + name)
+                    logger.log("CoreSched: ran out of units while scheduling sliver " + name)
                 else:
                     cpu = cpus.pop()
-                    logger.log("CoreSched: allocating cpu " + str(cpu) + " to slice " + name)
+                    logger.log("CoreSched: allocating unit " + str(cpu) + " to slice " + name)
                     reservations[name] = reservations.get(name,[]) + [cpu]
 
                 cores = cores-1
 
         # the leftovers go to everyone else
-        logger.log("CoreSched: allocating cpus " + str(cpus) + " to _default")
+        logger.log("CoreSched: allocating unit " + str(cpus) + " to _default")
         reservations["_default"] = cpus[:]
 
-        # now check and see if any of our reservations had the besteffort flag
+        # now check and see if any of our slices had the besteffort flag
         # set
         for name, rec in slivers.iteritems():
             rspec = rec["_rspec"]
-            cores = rspec.get("cpu_cores", 0)
+            cores = rspec.get(self.slice_attr_name, 0)
             (cores, bestEffort) = self.decodeCoreSpec(cores)
 
-            if not (reservations.get(name,[])):
-                # if there is no reservation for this slice, then it's already
-                # besteffort by default.
+            # if the bestEffort flag isn't set then we have nothing to do
+            if not bestEffort:
                 continue
 
-            if bestEffort:
+            # note that if a reservation is [], then we don't need to add
+            # bestEffort cores to it, since it is bestEffort by default.
+
+            if reservations.get(name,[]) != []:
                 reservations[name] = reservations[name] + reservations["_default"]
-                logger.log("CoreSched: adding besteffort cores to " + name + ". new cores = " + str(reservations[name]))
+                logger.log("CoreSched: adding besteffort units to " + name + ". new units = " + str(reservations[name]))
 
         self.reserveCores(reservations)
 
@@ -146,17 +161,20 @@ class CoreSched:
         self.reserveDefault(default)
 
         for cgroup in self.get_cgroups():
-            cpus = reservations.get(cgroup, default)
-
-            logger.log("CoreSched: reserving " + cgroup + " " + str(cpus))
+            if cgroup in reservations:
+                cpus = reservations[cgroup]
+                logger.log("CoreSched: reserving " + self.cgroup_var_name + " on " + cgroup + ": " + str(cpus))
+            else:
+                # no log message for default; too much verbosity in the common case
+                cpus = default
 
-            file("/dev/cgroup/" + cgroup + "/cpuset.cpus", "w").write( self.listToRange(cpus) + "\n" )
+            file("/dev/cgroup/" + cgroup + "/" + self.cgroup_var_name, "w").write( self.listToRange(cpus) + "\n" )
 
     def reserveDefault (self, cpus):
         if not os.path.exists("/etc/vservers/.defaults/cgroup"):
             os.makedirs("/etc/vservers/.defaults/cgroup")
 
-        file("/etc/vservers/.defaults/cgroup/cpuset.cpus", "w").write( self.listToRange(cpus) + "\n" )
+        file("/etc/vservers/.defaults/cgroup/" + self.cgroup_var_name, "w").write( self.listToRange(cpus) + "\n" )
 
     def listToRange (self, list):
         """ take a list of items [1,2,3,5,...] and return it as a range: "1-3,5"