2011/2/24 Juan Quintela <quint...@redhat.com>: > Yoshiaki Tamura <tamura.yoshi...@lab.ntt.co.jp> wrote: >> 2011/2/23 Juan Quintela <quint...@redhat.com>: >>> Yoshiaki Tamura <tamura.yoshi...@lab.ntt.co.jp> wrote: >>>> 2011/2/23 Juan Quintela <quint...@redhat.com>: > >>>> Although you're right, I would prefer to keep it so that somebody >>>> outside of migration may understand the status in the future if >>>> there are no harms. >>> >>> my plan is to move MigrationState inside migration.c, and then decide >>> what to export/not export. >> >> Well, it may be just a policy, but it's already exported, and I >> would like to keep it unless it bothers your plan. IIUC, I don't >> think it does. >> >>> Next thing to do is move migration to its >>> own thread. Before doing that, I need to know what parts are used/not >>> used outside migration.c. Removing it now means that nothing gets to >>> use it without needing a patch. >> >> I've once asked Anthony whether it's possible to make migration >> to different threads, but his answer was no due to hard >> dependency of qemu's internal code, and making migration to >> different threads are bad design. > > I know. But Anthony is seeing the light O:-)
I'm with you at making live migration fast, but let me comment a few. > Basically, without an own thread we are not able to: > - do anything else while on incoming migration > (namely using the monitor) It's not true. Just adding fixed headers to buffered file should be enough for that. I've done it for Kemari as you can see this (http://www.osrg.net/kemari/download/kemari-v0.2-fedora11.mov). > - do anything else than migration. We can try hard and let vcpus to > run, but we would still clog the io_thread. > - We are not able to saturate 10Gbit networking (basically we are doing > 2/3 level of bufferering (depending on how you count). I think current byte-based dirty bitmap for sending rams are responsible for this too. I've converted it to bit-based dirty and made traversing 100x faster. Also bypassing QEMUFile buffer in case of rams would boost to some degrees. Thanks, Yoshi > So, once code is there, I guess we will convince Anthony to commit it. > > Later, Juan. > >