+ Eric, Willem On 24/11/2016 17:12, Stefan Hajnoczi wrote: > I looked through the socket SO_BUSY_POLL and blk_mq poll support in > recent Linux kernels with an eye towards integrating the ongoing QEMU > polling work. The main missing feature is eventfd polling support which > I describe below. ... > State of polling in Linux > ------------------------- > SO_BUSY_POLL causes recvmsg(2), select(2), and poll(2) family system > calls to spin awaiting new receive packets. From what I can tell epoll > is not supported so that system call will sleep without polling.
At the time I sent out an RFC for epoll() SO_BUSY_POLL support. https://lkml.org/lkml/2013/8/21/192 In hindsight I think the way I tracked sockets was over-complicated. What I would do today would be to extend the API to allow the user to tell epoll which socket/queue combinations are interesting. I would love to collaborate on this with you, though I must confess that my resources at the moment are limited and the setup I used for testing no longer exists. -Eliezer
