Hello Peter, On Tue, Sep 28, 2021 at 7:51 PM Peter Xu <pet...@redhat.com> wrote: > > On Wed, Sep 22, 2021 at 07:24:20PM -0300, Leonardo Bras wrote: > > This patch series intends to enable MSG_ZEROCOPY in QIOChannel, and make > > use of it for multifd migration performance improvement. > > > > Patch #1 creates new callbacks for QIOChannel, allowing the implementation > > of asynchronous writing. > > > > Patch #2 implements async_write and async_flush on QIOChannelSocket, > > > > Patch #3 Makes use of async_write + async_flush to enable MSG_ZEROCOPY > > for migration using multifd nocomp. > > > > Results: > > So far, the resource usage of __sys_sendmsg() reduced 15 times, and the > > overall migration took 13-18% less time, based in synthetic workload. > > > > The objective is to reduce migration time in hosts with heavy cpu usage. > > My previous memory is that we'll add a capability bit for migration, so it'll > not be enabled until user specified it. Plan to do it in the next version?
You mean like I did in pre-V1, enabling ZEROCOPY for multifd it in QMP? Or is this something else? > > It'll still be okay if you want to separate the work of (1) qio channel > zero-copy support on sockets, and (2) apply zero copy to migration, then that > can be done in part 2. Your call. :) Ok :) > > Thanks, > > -- > Peter Xu > Thank you Peter, Best regards, Leonardo
