import xen.lowlevel.xc
import xen.lowlevel.xs
import string
import time
import qmemman_algo
import os
class DomainState:
def __init__(self, id):
self.meminfo = None #dictionary of memory info read from client
self.memory_actual = None #the current memory size
self.memory_maximum = None #the maximum memory size
self.mem_used = None #used memory, computed based on meminfo
self.id = id #domain id
self.last_target = 0 #the last memset target
class SystemState:
def __init__(self):
self.domdict = {}
self.xc = xen.lowlevel.xc.xc()
self.xs = xen.lowlevel.xs.xs()
self.BALOON_DELAY = 0.1
self.XEN_FREE_MEM_LEFT = 50*1024*1024
self.XEN_FREE_MEM_MIN = 25*1024*1024
def add_domain(self, id):
self.domdict[id] = DomainState(id)
def del_domain(self, id):
self.domdict.pop(id)
self.do_balance()
def get_free_xen_memory(self):
return self.xc.physinfo()['free_memory']*1024
# hosts = self.xend_session.session.xenapi.host.get_all()
# host_record = self.xend_session.session.xenapi.host.get_record(hosts[0])
# host_metrics_record = self.xend_session.session.xenapi.host_metrics.get_record(host_record["metrics"])
# ret = host_metrics_record["memory_free"]
# return long(ret)
#refresh information on memory assigned to all domains
def refresh_memactual(self):
for domain in self.xc.domain_getinfo():
id = str(domain['domid'])
if self.domdict.has_key(id):
self.domdict[id].memory_actual = domain['mem_kb']*1024
self.domdict[id].memory_maximum = self.xs.read('', '/local/domain/%s/memory/static-max' % str(id))
if not self.domdict[id].memory_maximum:
self.domdict[id].memory_maximum = domain['maxmem_kb']*1024
#the below works (and is fast), but then 'xm list' shows unchanged memory value
def mem_set(self, id, val):
print 'mem-set domain', id, 'to', val
self.domdict[id].last_target = val
self.xs.write('', '/local/domain/' + id + '/memory/target', str(val/1024))
#can happen in the middle of domain shutdown
#apparently xc.lowlevel throws exceptions too
try:
self.xc.domain_setmaxmem(int(id), val/1024 + 1024) # LIBXL_MAXMEM_CONSTANT=1024
self.xc.domain_set_target_mem(int(id), val/1024)
except:
pass
def mem_set_obsolete(self, id, val):
uuid = self.domdict[id].uuid
if val >= 2**31:
print 'limiting memory from ', val, 'to maxint because of xml-rpc lameness'
val = 2**31 - 1
print 'mem-set domain', id, 'to', val
try:
self.xend_session.session.xenapi.VM.set_memory_dynamic_max_live(uuid, val)
self.xend_session.session.xenapi.VM.set_memory_dynamic_min_live(uuid, val)
#can happen in the middle of domain shutdown
except XenAPI.Failure:
pass
#perform memory ballooning, across all domains, to add "memsize" to Xen free memory
def do_balloon(self, memsize):
MAX_TRIES = 20
niter = 0
prev_memory_actual = None
for i in self.domdict.keys():
self.domdict[i].no_progress = False
while True:
xenfree = self.get_free_xen_memory()
print 'got xenfree=', xenfree
if xenfree >= memsize + self.XEN_FREE_MEM_MIN:
return True
self.refresh_memactual()
if prev_memory_actual is not None:
for i in prev_memory_actual.keys():
if prev_memory_actual[i] == self.domdict[i].memory_actual:
#domain not responding to memset requests, remove it from donors
self.domdict[i].no_progress = True
print 'domain', i, 'stuck at', self.domdict[i].memory_actual
memset_reqs = qmemman_algo.balloon(memsize + self.XEN_FREE_MEM_LEFT - xenfree, self.domdict)
print 'requests:', memset_reqs
if niter > MAX_TRIES or len(memset_reqs) == 0:
return False
prev_memory_actual = {}
for i in memset_reqs:
dom, mem = i
self.mem_set(dom, mem)
prev_memory_actual[dom] = self.domdict[dom].memory_actual
time.sleep(self.BALOON_DELAY)
niter = niter + 1
def refresh_meminfo(self, domid, untrusted_meminfo_key):
qmemman_algo.refresh_meminfo_for_domain(self.domdict[domid], untrusted_meminfo_key)
self.do_balance()
#is the computed balance request big enough ?
#so that we do not trash with small adjustments
def is_balance_req_significant(self, memset_reqs, xenfree):
total_memory_transfer = 0
MIN_TOTAL_MEMORY_TRANSFER = 150*1024*1024
MIN_MEM_CHANGE_WHEN_UNDER_PREF = 15*1024*1024
for rq in memset_reqs:
dom, mem = rq
last_target = self.domdict[dom].last_target
memory_change = mem - last_target
total_memory_transfer += abs(memory_change)
pref = qmemman_algo.prefmem(self.domdict[dom])
if last_target > 0 and last_target < pref and memory_change > MIN_MEM_CHANGE_WHEN_UNDER_PREF:
print 'dom', dom, 'is below pref, allowing balance'
return True
return total_memory_transfer + abs(xenfree - self.XEN_FREE_MEM_LEFT) > MIN_TOTAL_MEMORY_TRANSFER
def print_stats(self, xenfree, memset_reqs):
for i in self.domdict.keys():
if self.domdict[i].meminfo is not None:
print 'dom' , i, 'act/pref', self.domdict[i].memory_actual, qmemman_algo.prefmem(self.domdict[i])
print 'xenfree=', xenfree, 'balance req:', memset_reqs
def do_balance(self):
if os.path.isfile('/var/run/qubes/do-not-membalance'):
return
self.refresh_memactual()
xenfree = self.get_free_xen_memory()
memset_reqs = qmemman_algo.balance(xenfree - self.XEN_FREE_MEM_LEFT, self.domdict)
if not self.is_balance_req_significant(memset_reqs, xenfree):
return
self.print_stats(xenfree, memset_reqs)
for rq in memset_reqs:
dom, mem = rq
self.mem_set(dom, mem)
# for i in self.domdict.keys():
# print 'domain ', i, ' meminfo=', self.domdict[i].meminfo, 'actual mem', self.domdict[i].memory_actual
# print 'domain ', i, 'actual mem', self.domdict[i].memory_actual
# print 'xen free mem', self.get_free_xen_memory()