[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH]fix hang on migration
hi, the migration process may be hang when you start another VM while the migration is under way. Eg. Start a VM: # xm create OVM_EL5U3_X86_PVHVM_4GB/vm.cfg Wait for the VM bootup, then start another VM while this VM is migration: # xm migrate -l OVM_EL5U3_X86_PVHVM_4GB localhost & # xm create OVM_EL5U1_X86_HVM_4GB/vm.cfg The migration will hang on: # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 543 2 r----- 110.1 OVM_EL5U1_X86_HVM_4GB 4 256 1 -b---- 39.6 OVM_EL5U3_X86_PVHVM_4GB 5 512 1 --p--- 0.0 The migration will only finish after shutting down VM OVM_EL5U1_X86_HVM_4GB. This is because we are using a threaded model in xend, and the migration thread is running in the same context, and we are using pipes/sockets in migration. So the write side of the pipe/socket created while migration will inherited to children, thus the reading side of the pipe/socket will hang if there is a child forked and the child never end up (like qemu-dm). So we should close all inherited open file descriptors in every forked process. Ian: please review the patch against qemu-dm forking. Signed-off-by: Zhigang Wang <zhigang.x.wang@xxxxxxxxxx> Reviewed-by: Xiaowei Hu <xiaowei.hu@xxxxxxxxxx> thanks, zhigang diff -Nurap xen-unstable.orig/tools/python/xen/util/oshelp.py xen-unstable/tools/python/xen/util/oshelp.py --- xen-unstable.orig/tools/python/xen/util/oshelp.py 2009-07-24 16:07:59.000000000 +0800 +++ xen-unstable/tools/python/xen/util/oshelp.py 2009-07-24 16:52:32.000000000 +0800 @@ -1,6 +1,19 @@ import fcntl import os +def close_fds(pass_fds=()): + try: + MAXFD = os.sysconf('SC_OPEN_MAX') + except: + MAXFD = 256 + for i in range(3, MAXFD): + if i in pass_fds: + continue + try: + os.close(i) + except OSError: + pass + def fcntl_setfd_cloexec(file, bool): f = fcntl.fcntl(file, fcntl.F_GETFD) if bool: f |= fcntl.FD_CLOEXEC diff -Nurap xen-unstable.orig/tools/python/xen/util/xpopen.py xen-unstable/tools/python/xen/util/xpopen.py --- xen-unstable.orig/tools/python/xen/util/xpopen.py 2009-07-24 16:07:59.000000000 +0800 +++ xen-unstable/tools/python/xen/util/xpopen.py 2009-07-24 17:17:28.000000000 +0800 @@ -85,7 +85,7 @@ class xPopen3: sts = -1 # Child not completed yet - def __init__(self, cmd, capturestderr=False, bufsize=-1, passfd=()): + def __init__(self, cmd, capturestderr=False, bufsize=-1, passfd=(), env=None): """The parameter 'cmd' is the shell command to execute in a sub-process. The 'capturestderr' flag, if true, specifies that the object should capture standard error output of the child process. @@ -128,6 +128,10 @@ class xPopen3: pass try: os.execvp(cmd[0], cmd) + if env is None: + os.execvp(cmd[0], cmd) + else: + os.execvpe(cmd[0], cmd, env) finally: os._exit(127) @@ -154,16 +158,26 @@ class xPopen3: return self.sts -def xpopen2(cmd, bufsize=-1, mode='t', passfd=[]): +def xpopen2(cmd, bufsize=-1, mode='t', passfd=[], env=None): """Execute the shell command 'cmd' in a sub-process. If 'bufsize' is specified, it sets the buffer size for the I/O pipes. The file objects (child_stdout, child_stdin) are returned.""" - inst = xPopen3(cmd, False, bufsize, passfd) + inst = xPopen3(cmd, False, bufsize, passfd, env) return inst.fromchild, inst.tochild -def xpopen3(cmd, bufsize=-1, mode='t', passfd=[]): +def xpopen3(cmd, bufsize=-1, mode='t', passfd=[], env=None): """Execute the shell command 'cmd' in a sub-process. If 'bufsize' is specified, it sets the buffer size for the I/O pipes. The file objects (child_stdout, child_stdin, child_stderr) are returned.""" - inst = xPopen3(cmd, True, bufsize, passfd) + inst = xPopen3(cmd, True, bufsize, passfd, env) return inst.fromchild, inst.tochild, inst.childerr + +def call(*popenargs, **kwargs): + """Run command with arguments. Wait for command to complete, then + return the status. + + The arguments are the same as for the xPopen3 constructor. Example: + + status = call("ls -l") + """ + return xPopen3(*popenargs, **kwargs).wait() diff -Nurap xen-unstable.orig/tools/python/xen/util/xsm/acm/acm.py xen-unstable/tools/python/xen/util/xsm/acm/acm.py --- xen-unstable.orig/tools/python/xen/util/xsm/acm/acm.py 2009-07-24 16:07:59.000000000 +0800 +++ xen-unstable/tools/python/xen/util/xsm/acm/acm.py 2009-07-24 17:27:30.000000000 +0800 @@ -31,7 +31,7 @@ from xen.xend import XendConstants from xen.xend import XendOptions from xen.xend.XendLogging import log from xen.xend.XendError import VmError -from xen.util import dictio, xsconstants, auxbin +from xen.util import dictio, xsconstants, auxbin, xpopen from xen.xend.XendConstants import * #global directories and tools for security management @@ -1710,7 +1710,7 @@ def run_resource_label_change_script(res log.info("Running resource label change script %s: %s" % (script, parms)) parms.update(os.environ) - os.spawnve(os.P_WAIT, script[0], script, parms) + xpopen.call(" ".join(script, params)) else: log.info("No script given for relabeling of resources.") if not __script_runner: diff -Nurap xen-unstable.orig/tools/python/xen/xend/image.py xen-unstable/tools/python/xen/xend/image.py --- xen-unstable.orig/tools/python/xen/xend/image.py 2009-07-24 16:07:59.000000000 +0800 +++ xen-unstable/tools/python/xen/xend/image.py 2009-07-27 17:37:20.000000000 +0800 @@ -438,9 +438,7 @@ class ImageHandler: os.dup2(null, 0) os.dup2(logfd, 1) os.dup2(logfd, 2) - os.close(null) - os.close(logfd) - self.sentinel_fifo.close() + oshelp.close_fds((sentinel_write.fileno(),)) try: os.execve(self.device_model, args, env) except Exception, e: diff -Nurap xen-unstable.orig/tools/python/xen/xend/server/BlktapController.py xen-unstable/tools/python/xen/xend/server/BlktapController.py --- xen-unstable.orig/tools/python/xen/xend/server/BlktapController.py 2009-07-24 16:07:59.000000000 +0800 +++ xen-unstable/tools/python/xen/xend/server/BlktapController.py 2009-07-24 17:40:15.000000000 +0800 @@ -1,9 +1,9 @@ # Copyright (c) 2005, XenSource Ltd. import string, re -import popen2 from xen.xend.server.blkif import BlkifController from xen.xend.XendLogging import log +from xen.util.xpopen import xPopen3 phantomDev = 0; phantomId = 0; @@ -34,7 +34,7 @@ blktap_disk_types = blktap1_disk_types + def doexec(args, inputtext=None): """Execute a subprocess, then return its return code, stdout and stderr""" - proc = popen2.Popen3(args, True) + proc = xPopen3(args, True) if inputtext != None: proc.tochild.write(inputtext) stdout = proc.fromchild diff -Nurap xen-unstable.orig/tools/python/xen/xend/Vifctl.py xen-unstable/tools/python/xen/xend/Vifctl.py --- xen-unstable.orig/tools/python/xen/xend/Vifctl.py 2009-07-24 16:07:59.000000000 +0800 +++ xen-unstable/tools/python/xen/xend/Vifctl.py 2009-07-24 17:26:38.000000000 +0800 @@ -18,10 +18,9 @@ """Xend interface to networking control scripts. """ -import os import XendOptions - +from xen.util import xpopen def network(op): """Call a network control script. @@ -33,4 +32,4 @@ def network(op): script = XendOptions.instance().get_network_script() if script: script.insert(1, op) - os.spawnv(os.P_WAIT, script[0], script) + xpopen.call(script) diff -Nurap xen-unstable.orig/tools/python/xen/xend/XendBootloader.py xen-unstable/tools/python/xen/xend/XendBootloader.py --- xen-unstable.orig/tools/python/xen/xend/XendBootloader.py 2009-07-24 16:07:59.000000000 +0800 +++ xen-unstable/tools/python/xen/xend/XendBootloader.py 2009-07-24 17:43:22.000000000 +0800 @@ -17,7 +17,7 @@ import random import shlex from xen.xend import sxp -from xen.util import mkdir +from xen.util import mkdir, oshelp from XendLogging import log from XendError import VmError @@ -113,6 +113,7 @@ def bootloader(blexec, disk, dom, quiet log.debug("Launching bootloader as %s." % str(args)) env = os.environ.copy() env['TERM'] = 'vt100' + oshelp.close_fds() os.execvpe(args[0], args, env) except OSError, e: print e _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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