ia64/xen-unstable

changeset 16268:09d8b6eb3131

xend: Reduce xenstore transactions when listing domains

In summary, this allows a xenstore transaction object to be passed
around the various device controllers, so that they don't have to do
lots of singleton transactions. Transactions have very heavy I/O
impact from xenstored so reducing their number is important.

When running 3 guests, this patch reduces the impact of 'xm list
--long' from 176 transactions, scaling O(n) with guests, to 26
transactions with O(1) scaling.

I have previously attempted to also address the same issue with 'xm
create' but that's much harder since the device front/back handshake
requires that XenD use a number of small transactions. So i've not
changed anything here.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
author Keir Fraser <keir@xensource.com>
date Tue Oct 30 09:19:43 2007 +0000 (2007-10-30)
parents 4034317507de
children d25ab83a89e3
files tools/python/xen/xend/XendConfig.py tools/python/xen/xend/XendDomain.py tools/python/xen/xend/XendDomainInfo.py tools/python/xen/xend/server/ConsoleController.py tools/python/xen/xend/server/DevController.py tools/python/xen/xend/server/blkif.py tools/python/xen/xend/server/netif.py tools/python/xen/xend/server/pciif.py tools/python/xen/xend/server/tpmif.py tools/python/xen/xend/server/vfbif.py
line diff
     1.1 --- a/tools/python/xen/xend/XendConfig.py	Mon Oct 29 16:49:02 2007 +0000
     1.2 +++ b/tools/python/xen/xend/XendConfig.py	Tue Oct 30 09:19:43 2007 +0000
     1.3 @@ -28,6 +28,7 @@ from xen.xend.XendError import VmError
     1.4  from xen.xend.XendDevices import XendDevices
     1.5  from xen.xend.PrettyPrint import prettyprintstring
     1.6  from xen.xend.XendConstants import DOM_STATE_HALTED
     1.7 +from xen.xend.xenstore.xstransact import xstransact
     1.8  from xen.xend.server.BlktapController import blktap_disk_types
     1.9  from xen.xend.server.netif import randomMAC
    1.10  from xen.util.blkif import blkdev_name_to_number
    1.11 @@ -941,36 +942,43 @@ class XendConfig(dict):
    1.12  
    1.13          # Marshall devices (running or from configuration)
    1.14          if not ignore_devices:
    1.15 -            for cls in XendDevices.valid_devices():
    1.16 -                found = False
    1.17 +            txn = xstransact()
    1.18 +            try:
    1.19 +                for cls in XendDevices.valid_devices():
    1.20 +                    found = False
    1.21                  
    1.22 -                # figure if there is a dev controller is valid and running
    1.23 -                if domain and domain.getDomid() != None:
    1.24 -                    try:
    1.25 -                        controller = domain.getDeviceController(cls)
    1.26 -                        configs = controller.configurations()
    1.27 -                        for config in configs:
    1.28 -                            if sxp.name(config) in ('vbd', 'tap'):
    1.29 -                                # The bootable flag is never written to the
    1.30 -                                # store as part of the device config.
    1.31 -                                dev_uuid = sxp.child_value(config, 'uuid')
    1.32 -                                dev_type, dev_cfg = self['devices'][dev_uuid]
    1.33 -                                is_bootable = dev_cfg.get('bootable', 0)
    1.34 -                                config.append(['bootable', int(is_bootable)])
    1.35 +                    # figure if there is a dev controller is valid and running
    1.36 +                    if domain and domain.getDomid() != None:
    1.37 +                        try:
    1.38 +                            controller = domain.getDeviceController(cls)
    1.39 +                            configs = controller.configurations(txn)
    1.40 +                            for config in configs:
    1.41 +                                if sxp.name(config) in ('vbd', 'tap'):
    1.42 +                                    # The bootable flag is never written to the
    1.43 +                                    # store as part of the device config.
    1.44 +                                    dev_uuid = sxp.child_value(config, 'uuid')
    1.45 +                                    dev_type, dev_cfg = self['devices'][dev_uuid]
    1.46 +                                    is_bootable = dev_cfg.get('bootable', 0)
    1.47 +                                    config.append(['bootable', int(is_bootable)])
    1.48  
    1.49 -                            sxpr.append(['device', config])
    1.50 +                                sxpr.append(['device', config])
    1.51  
    1.52 -                        found = True
    1.53 -                    except:
    1.54 -                        log.exception("dumping sxp from device controllers")
    1.55 -                        pass
    1.56 +                            found = True
    1.57 +                        except:
    1.58 +                            log.exception("dumping sxp from device controllers")
    1.59 +                            pass
    1.60                      
    1.61 -                # if we didn't find that device, check the existing config
    1.62 -                # for a device in the same class
    1.63 -                if not found:
    1.64 -                    for dev_type, dev_info in self.all_devices_sxpr():
    1.65 -                        if dev_type == cls:
    1.66 -                            sxpr.append(['device', dev_info])
    1.67 +                    # if we didn't find that device, check the existing config
    1.68 +                    # for a device in the same class
    1.69 +                    if not found:
    1.70 +                        for dev_type, dev_info in self.all_devices_sxpr():
    1.71 +                            if dev_type == cls:
    1.72 +                                sxpr.append(['device', dev_info])
    1.73 +
    1.74 +                txn.commit()
    1.75 +            except:
    1.76 +                txn.abort()
    1.77 +                raise
    1.78  
    1.79          return sxpr    
    1.80      
     2.1 --- a/tools/python/xen/xend/XendDomain.py	Mon Oct 29 16:49:02 2007 +0000
     2.2 +++ b/tools/python/xen/xend/XendDomain.py	Tue Oct 30 09:19:43 2007 +0000
     2.3 @@ -393,13 +393,22 @@ class XendDomain:
     2.4          @rtype: None
     2.5          """
     2.6  
     2.7 +        txn = xstransact()
     2.8 +        try:
     2.9 +            self._refreshTxn(txn, refresh_shutdown)
    2.10 +            txn.commit()
    2.11 +        except:
    2.12 +            txn.abort()
    2.13 +            raise
    2.14 +
    2.15 +    def _refreshTxn(self, transaction, refresh_shutdown):
    2.16          running = self._running_domains()
    2.17          # Add domains that are not already tracked but running in Xen,
    2.18          # and update domain state for those that are running and tracked.
    2.19          for dom in running:
    2.20              domid = dom['domid']
    2.21              if domid in self.domains:
    2.22 -                self.domains[domid].update(dom, refresh_shutdown)
    2.23 +                self.domains[domid].update(dom, refresh_shutdown, transaction)
    2.24              elif domid not in self.domains and dom['dying'] != 1:
    2.25                  try:
    2.26                      new_dom = XendDomainInfo.recreate(dom, False)
     3.1 --- a/tools/python/xen/xend/XendDomainInfo.py	Mon Oct 29 16:49:02 2007 +0000
     3.2 +++ b/tools/python/xen/xend/XendDomainInfo.py	Tue Oct 30 09:19:43 2007 +0000
     3.3 @@ -819,12 +819,15 @@ class XendDomainInfo:
     3.4  
     3.5          self._update_consoles()
     3.6  
     3.7 -    def _update_consoles(self):
     3.8 +    def _update_consoles(self, transaction = None):
     3.9          if self.domid == None or self.domid == 0:
    3.10              return
    3.11  
    3.12          # Update VT100 port if it exists
    3.13 -        self.console_port = self.readDom('console/port')
    3.14 +        if transaction is None:
    3.15 +            self.console_port = self.readDom('console/port')
    3.16 +        else:
    3.17 +            self.console_port = self.readDomTxn(transaction, 'console/port')
    3.18          if self.console_port is not None:
    3.19              serial_consoles = self.info.console_get_all('vt100')
    3.20              if not serial_consoles:
    3.21 @@ -837,7 +840,10 @@ class XendDomainInfo:
    3.22                  
    3.23  
    3.24          # Update VNC port if it exists and write to xenstore
    3.25 -        vnc_port = self.readDom('console/vnc-port')
    3.26 +        if transaction is None:
    3.27 +            vnc_port = self.readDom('console/vnc-port')
    3.28 +        else:
    3.29 +            vnc_port = self.readDomTxn(transaction, 'console/vnc-port')
    3.30          if vnc_port is not None:
    3.31              for dev_uuid, (dev_type, dev_info) in self.info['devices'].items():
    3.32                  if dev_type == 'vfb':
    3.33 @@ -872,6 +878,27 @@ class XendDomainInfo:
    3.34      def storeVm(self, *args):
    3.35          return xstransact.Store(self.vmpath, *args)
    3.36  
    3.37 +
    3.38 +    def _readVmTxn(self, transaction,  *args):
    3.39 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.40 +        return transaction.read(*paths)
    3.41 +
    3.42 +    def _writeVmTxn(self, transaction,  *args):
    3.43 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.44 +        return transaction.write(*paths)
    3.45 +
    3.46 +    def _removeVmTxn(self, transaction,  *args):
    3.47 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.48 +        return transaction.remove(*paths)
    3.49 +
    3.50 +    def _gatherVmTxn(self, transaction,  *args):
    3.51 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.52 +        return transaction.gather(paths)
    3.53 +
    3.54 +    def storeVmTxn(self, transaction,  *args):
    3.55 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.56 +        return transaction.store(*paths)
    3.57 +
    3.58      #
    3.59      # Function to update xenstore /dom/*
    3.60      #
    3.61 @@ -891,6 +918,28 @@ class XendDomainInfo:
    3.62      def storeDom(self, *args):
    3.63          return xstransact.Store(self.dompath, *args)
    3.64  
    3.65 +
    3.66 +    def readDomTxn(self, transaction, *args):
    3.67 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.68 +        return transaction.read(*paths)
    3.69 +
    3.70 +    def gatherDomTxn(self, transaction, *args):
    3.71 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.72 +        return transaction.gather(*paths)
    3.73 +
    3.74 +    def _writeDomTxn(self, transaction, *args):
    3.75 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.76 +        return transaction.write(*paths)
    3.77 +
    3.78 +    def _removeDomTxn(self, transaction, *args):
    3.79 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.80 +        return transaction.remove(*paths)
    3.81 +
    3.82 +    def storeDomTxn(self, transaction, *args):
    3.83 +        paths = map(lambda x: self.vmpath + "/" + x, args)
    3.84 +        return transaction.store(*paths)
    3.85 +
    3.86 +
    3.87      def _recreateDom(self):
    3.88          complete(self.dompath, lambda t: self._recreateDomFunc(t))
    3.89  
    3.90 @@ -2223,7 +2272,7 @@ class XendDomainInfo:
    3.91                             (" as domain %s" % str(dom.domid)) or ""))
    3.92          
    3.93  
    3.94 -    def update(self, info = None, refresh = True):
    3.95 +    def update(self, info = None, refresh = True, transaction = None):
    3.96          """Update with info from xc.domain_getinfo().
    3.97          """
    3.98          log.trace("XendDomainInfo.update(%s) on domain %s", info,
    3.99 @@ -2246,7 +2295,7 @@ class XendDomainInfo:
   3.100          # TODO: we should eventually get rid of old_dom_states
   3.101  
   3.102          self.info.update_config(info)
   3.103 -        self._update_consoles()
   3.104 +        self._update_consoles(transaction)
   3.105          
   3.106          if refresh:
   3.107              self.refreshShutdown(info)
     4.1 --- a/tools/python/xen/xend/server/ConsoleController.py	Mon Oct 29 16:49:02 2007 +0000
     4.2 +++ b/tools/python/xen/xend/server/ConsoleController.py	Tue Oct 30 09:19:43 2007 +0000
     4.3 @@ -19,9 +19,12 @@ class ConsoleController(DevController):
     4.4          return (self.allocateDeviceID(), back, {})
     4.5  
     4.6  
     4.7 -    def getDeviceConfiguration(self, devid):
     4.8 -        result = DevController.getDeviceConfiguration(self, devid)
     4.9 -        devinfo = self.readBackend(devid, *self.valid_cfg)
    4.10 +    def getDeviceConfiguration(self, devid, transaction = None):
    4.11 +        result = DevController.getDeviceConfiguration(self, devid, transaction)
    4.12 +        if transaction is None:
    4.13 +            devinfo = self.readBackend(devid, *self.valid_cfg)
    4.14 +        else:
    4.15 +            devinfo = self.readBackendTxn(transaction, devid, *self.valid_cfg)
    4.16          config = dict(zip(self.valid_cfg, devinfo))
    4.17          config = dict([(key, val) for key, val in config.items()
    4.18                         if val != None])
     5.1 --- a/tools/python/xen/xend/server/DevController.py	Mon Oct 29 16:49:02 2007 +0000
     5.2 +++ b/tools/python/xen/xend/server/DevController.py	Tue Oct 30 09:19:43 2007 +0000
     5.3 @@ -239,15 +239,15 @@ class DevController:
     5.4  
     5.5          self.vm._removeVm("device/%s/%d" % (self.deviceClass, dev))
     5.6  
     5.7 -    def configurations(self):
     5.8 -        return map(self.configuration, self.deviceIDs())
     5.9 +    def configurations(self, transaction = None):
    5.10 +        return map(lambda x: self.configuration(x, transaction), self.deviceIDs(transaction))
    5.11  
    5.12  
    5.13 -    def configuration(self, devid):
    5.14 +    def configuration(self, devid, transaction = None):
    5.15          """@return an s-expression giving the current configuration of the
    5.16          specified device.  This would be suitable for giving to {@link
    5.17          #createDevice} in order to recreate that device."""
    5.18 -        configDict = self.getDeviceConfiguration(devid)
    5.19 +        configDict = self.getDeviceConfiguration(devid, transaction)
    5.20          sxpr = [self.deviceClass]
    5.21          for key, val in configDict.items():
    5.22              if isinstance(val, (types.ListType, types.TupleType)):
    5.23 @@ -273,13 +273,16 @@ class DevController:
    5.24                                     'id', devid]]
    5.25  
    5.26  
    5.27 -    def getDeviceConfiguration(self, devid):
    5.28 +    def getDeviceConfiguration(self, devid, transaction = None):
    5.29          """Returns the configuration of a device.
    5.30  
    5.31          @note: Similar to L{configuration} except it returns a dict.
    5.32          @return: dict
    5.33          """
    5.34 -        backdomid = xstransact.Read(self.frontendPath(devid), "backend-id")
    5.35 +        if transaction is None:
    5.36 +            backdomid = xstransact.Read(self.frontendPath(devid), "backend-id")
    5.37 +        else:
    5.38 +            backdomid = transaction.read(self.frontendPath(devid) + "/backend-id")
    5.39          if backdomid is None:
    5.40              raise VmError("Device %s not connected" % devid)
    5.41  
    5.42 @@ -416,14 +419,28 @@ class DevController:
    5.43          else:
    5.44              raise VmError("Device %s not connected" % devid)
    5.45  
    5.46 +    def readBackendTxn(self, transaction, devid, *args):
    5.47 +        frontpath = self.frontendPath(devid)
    5.48 +        backpath = transaction.read(frontpath + "/backend")
    5.49 +        if backpath:
    5.50 +            paths = map(lambda x: backpath + "/" + x, args)
    5.51 +            return transaction.read(*paths)
    5.52 +        else:
    5.53 +            raise VmError("Device %s not connected" % devid)
    5.54 +
    5.55      def readFrontend(self, devid, *args):
    5.56          return xstransact.Read(self.frontendPath(devid), *args)
    5.57  
    5.58 +    def readFrontendTxn(self, transaction, devid, *args):
    5.59 +        paths = map(lambda x: self.frontendPath(devid) + "/" + x, args)
    5.60 +        return transaction.read(*paths)
    5.61 +
    5.62      def deviceIDs(self, transaction = None):
    5.63          """@return The IDs of each of the devices currently configured for
    5.64          this instance's deviceClass.
    5.65          """
    5.66          fe = self.backendRoot()
    5.67 +
    5.68          if transaction:
    5.69              return map(lambda x: int(x.split('/')[-1]), transaction.list(fe))
    5.70          else:
     6.1 --- a/tools/python/xen/xend/server/blkif.py	Mon Oct 29 16:49:02 2007 +0000
     6.2 +++ b/tools/python/xen/xend/server/blkif.py	Tue Oct 30 09:19:43 2007 +0000
     6.3 @@ -124,19 +124,26 @@ class BlkifController(DevController):
     6.4                            (self.deviceClass, devid, config))
     6.5  
     6.6  
     6.7 -    def getDeviceConfiguration(self, devid):
     6.8 +    def getDeviceConfiguration(self, devid, transaction = None):
     6.9          """Returns the configuration of a device.
    6.10  
    6.11          @note: Similar to L{configuration} except it returns a dict.
    6.12          @return: dict
    6.13          """
    6.14 -        config = DevController.getDeviceConfiguration(self, devid)
    6.15 -        devinfo = self.readBackend(devid, 'dev', 'type', 'params', 'mode',
    6.16 -                                   'uuid')
    6.17 +        config = DevController.getDeviceConfiguration(self, devid, transaction)
    6.18 +        if transaction is None:
    6.19 +            devinfo = self.readBackend(devid, 'dev', 'type', 'params', 'mode',
    6.20 +                                       'uuid')
    6.21 +        else:
    6.22 +            devinfo = self.readBackendTxn(transaction, devid,
    6.23 +                                          'dev', 'type', 'params', 'mode', 'uuid')
    6.24          dev, typ, params, mode, uuid = devinfo
    6.25          
    6.26          if dev:
    6.27 -            dev_type = self.readFrontend(devid, 'device-type')
    6.28 +            if transaction is None:
    6.29 +                dev_type = self.readFrontend(devid, 'device-type')
    6.30 +            else:
    6.31 +                dev_type = self.readFrontendTxn(transaction, devid, 'device-type')
    6.32              if dev_type:
    6.33                  dev += ':' + dev_type
    6.34              config['dev'] = dev
     7.1 --- a/tools/python/xen/xend/server/netif.py	Mon Oct 29 16:49:02 2007 +0000
     7.2 +++ b/tools/python/xen/xend/server/netif.py	Tue Oct 30 09:19:43 2007 +0000
     7.3 @@ -183,17 +183,20 @@ class NetifController(DevController):
     7.4                                "network device")
     7.5  
     7.6  
     7.7 -    def getDeviceConfiguration(self, devid):
     7.8 +    def getDeviceConfiguration(self, devid, transaction = None):
     7.9          """@see DevController.configuration"""
    7.10  
    7.11 -        result = DevController.getDeviceConfiguration(self, devid)
    7.12 +        result = DevController.getDeviceConfiguration(self, devid, transaction)
    7.13  
    7.14          config_path = "device/%s/%d/" % (self.deviceClass, devid)
    7.15          devinfo = ()
    7.16          for x in ( 'script', 'ip', 'bridge', 'mac',
    7.17                     'type', 'vifname', 'rate', 'uuid', 'model', 'accel',
    7.18                     'security_label'):
    7.19 -            y = self.vm._readVm(config_path + x)
    7.20 +            if transaction is None:
    7.21 +                y = self.vm._readVm(config_path + x)
    7.22 +            else:
    7.23 +                y = self.vm._readVmTxn(transaction, config_path + x)
    7.24              devinfo += (y,)
    7.25          (script, ip, bridge, mac, typ, vifname, rate, uuid,
    7.26           model, accel, security_label) = devinfo
     8.1 --- a/tools/python/xen/xend/server/pciif.py	Mon Oct 29 16:49:02 2007 +0000
     8.2 +++ b/tools/python/xen/xend/server/pciif.py	Tue Oct 30 09:19:43 2007 +0000
     8.3 @@ -78,8 +78,8 @@ class PciController(DevController):
     8.4          back['uuid'] = config.get('uuid','')
     8.5          return (0, back, {})
     8.6  
     8.7 -    def getDeviceConfiguration(self, devid):
     8.8 -        result = DevController.getDeviceConfiguration(self, devid)
     8.9 +    def getDeviceConfiguration(self, devid, transaction = None):
    8.10 +        result = DevController.getDeviceConfiguration(self, devid, transaction)
    8.11          num_devs = self.readBackend(devid, 'num_devs')
    8.12          pci_devs = []
    8.13          
     9.1 --- a/tools/python/xen/xend/server/tpmif.py	Mon Oct 29 16:49:02 2007 +0000
     9.2 +++ b/tools/python/xen/xend/server/tpmif.py	Tue Oct 30 09:19:43 2007 +0000
     9.3 @@ -75,9 +75,9 @@ class TPMifController(DevController):
     9.4  
     9.5          return (devid, back, front)
     9.6  
     9.7 -    def getDeviceConfiguration(self, devid):
     9.8 +    def getDeviceConfiguration(self, devid, transaction = None):
     9.9          """Returns the configuration of a device"""
    9.10 -        result = DevController.getDeviceConfiguration(self, devid)
    9.11 +        result = DevController.getDeviceConfiguration(self, devid, transaction)
    9.12  
    9.13          (instance, uuid, type) = \
    9.14                             self.readBackend(devid, 'instance',
    10.1 --- a/tools/python/xen/xend/server/vfbif.py	Mon Oct 29 16:49:02 2007 +0000
    10.2 +++ b/tools/python/xen/xend/server/vfbif.py	Tue Oct 30 09:19:43 2007 +0000
    10.3 @@ -27,10 +27,13 @@ class VfbifController(DevController):
    10.4          return (devid, back, {})
    10.5  
    10.6  
    10.7 -    def getDeviceConfiguration(self, devid):
    10.8 -        result = DevController.getDeviceConfiguration(self, devid)
    10.9 +    def getDeviceConfiguration(self, devid, transaction = None):
   10.10 +        result = DevController.getDeviceConfiguration(self, devid, transaction)
   10.11  
   10.12 -        devinfo = self.readBackend(devid, *CONFIG_ENTRIES)
   10.13 +        if transaction is None:
   10.14 +            devinfo = self.readBackend(devid, *CONFIG_ENTRIES)
   10.15 +        else:
   10.16 +            devinfo = self.readBackendTxn(transaction, devid, *CONFIG_ENTRIES)
   10.17          return dict([(CONFIG_ENTRIES[i], devinfo[i])
   10.18                       for i in range(len(CONFIG_ENTRIES))
   10.19                       if devinfo[i] is not None])