sorry ;-). attached this time. Keir Fraser wrote: > Patch not attached. > > > On 29/07/2009 08:50, "Zhigang Wang" wrote: > >> Hi Keir, >> >> The hang happens often when you runs many VM simultaneously. So I'd like >> this patch go to 3.4-testing as well. >> >> This is the regenerated patch against xen-3.4-testing. >> >> Signed-off-by: Zhigang Wang >> Reviewed-by: Xiaowei Hu >> >> thanks, >> >> zhigang >> >> Zhigang Wang wrote: >>> 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 >>> Reviewed-by: Xiaowei Hu >>> >>> thanks, >>> >>> zhigang >>> >>> >>> >>> >>> >>> >>> ------------------------------------------------------------------------ >>> >>> _______________________________________________ >>> Xen-devel mailing list >>> Xen-devel@lists.xensource.com >>> http://lists.xensource.com/xen-devel > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel