2010/5/3 Charles Duffy <charles@xxxxxxxxx>: > ...or more particularly, in ram_bytes_remaining() called by do_info_migrate(); > oddly, this is much more pronounced when running with <emulator> pointing at a > shim prepending -no-kvm-irqchip to the invoked command line. > > This VM was intended to be paused for the save event (if my software was doing > its job correctly), so we shouldn't be spending time running the guest CPU and > writing updates for already-once-written blocks. > > I'm seeing much more CPU time spent inside qemu-kvm than in the exec'd lzop > process compressing and writing the data stream; on attaching gdb and taking > some stack traces to sample where execution time was spent, it appeared that we > were spending our time responding to requests from the monitor. > > The question then -- is the 50ms poll in qemuDomainWaitForMigrationComplete > (called from qemudDomainSave) perhaps too frequent? > > Thanks! What's the libvirt version? Maybe the "Poll for migration end every 50ms instead of 50us" [1] commit (part of 0.8.1) fixes your problem, if you're currently using libvirt < 0.8.1. [1] http://libvirt.org/git/?p=libvirt.git;a=commit;h=e2c059485cf062bf1f9066237039b6e398a2fe33 Matthias -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list