Re: [libvirt] [RFC] libvirt support multi-thread compression for live migration

On 2015年06月04日 20:09, Jiri Denemark wrote: > On Tue, Jun 02, 2015 at 11:02:27 -0600, Eric Blake wrote: >> On 06/02/2015 07:56 AM, Qiao, Liyong wrote: >>> Hi Eric >>> Thanks for replying the mail, replied in lines. >>> >>>> +virdomainMigrateGetParameters(virDomainPtr domain, >>>> + int *level, >>>> + int *threads, >>>> + int *dthreads, >>>> + int flags) >>>> + >>> I'd rather we used virTypedParameters, to make it easier to use the same API to pass ALL future possible tuning parameters, rather than just hard-coding to only the parameters of this one feature. >>> >>> Okay ,that sound good, but if virTypedParameters can be passed to qemu_driver such as qemu_monitor_json.c qemu_monitor_text.c ? >> [Your quoting style makes it very hard to distinguish original text from >> added text. Please consider changing your outgoing mail process to >> ensure that you add another level of quoting to all previous text so >> that your added text is the only unquoted text. Also, configure your >> mailer to wrap long lines.] >> >> Use existing API for a guide - for example, virDomainSetBlockIoTune >> takes virTypedParamters, as well as defines a specific set of parameters >> that it will understand. > And do we actually need to changed these migration parameters on the fly > when migration is already running. I can imagine we would need to do so > for some parameters but multithreaded compression sounds like something > that needs to be configured when migration starts and there's nothing to > be tuned on the fly. If this is the case, I think we should just add > these new parameters to virDomainMigrate3 instead of requiring another > API to be called to actually configure multithreaded compression. > > The separate API makes it a bit harder to repeat migration (which > previously failed) with a different parameters (e.g., without > multithreaded compression). hi jirka thanks for your advice, that make sense for me. if I understanding you correctly, then we need only do this virsh migrate --live --compressed --compress-level 1--compress-threads 8 --decompress-threads 2 and all compressed parameters (compress-level ,compress-threads, decompress-threads) only be specified when we do call virDomainMigrate3 instead of expose to user by 'virsh migrate-setparameters' ?