On Tue, 05/19 16:02, Stefan Hajnoczi wrote: > On Tue, May 19, 2015 at 10:50:57AM +0000, Fam Zheng wrote: > > v3: Replace previous 13 with a simple return type conversion patch. > > Drop RFC. > > > > This carries out the mandate in the comment of qemu_set_fd_handler2 and > > removes > > fd_read_poll from the code base, because it will make the work easier to > > convert ppoll to epoll in main loop. Also, the aio interface doesn't have a > > read poll callback, which means this conversion woule be necessary if we > > want > > to move iohandler fds from main loop to AioContext. > > > > There are five users of the read poll callback now: qemu-nbd, l2tpv3, > > netmap, > > socket and tap, which are all covered. > > > > Patch 1 adds a stub for qemu_set_fd_handler which will be referenced in > > coming > > patches. > > > > Patch 2 converts qemu-nbd which compares two global numbers in the > > fd_read_poll > > callback. > > > > Patches 3~6 converts the four net devices, all of which checks > > qemu_can_send_packet() in the callback. > > > > Patch 7 and 8 finally removes the function. > > > > The rest patches are cleanup for the unuseful return value of > > qemu_set_fd_handler. > > > > Please review! > > I looked at the first few patches. > > The qemu-nbd.c conversion is good. It finds locations where read_poll > state transitions happen and updates file descriptor monitoring there.
Paolo, will you apply the qemu-nbd.c patch? I'll split net patches into a separate series. > > The l2tpv3 and netmap conversion throws away read_poll and introduces > problems instead. > > Please look at the patches again and either: > > 1. Convert everything like you converted qemu-nbd.c. This is a > conservative approach and we can be confident that behavior is > unchanged. OK, I'll try this. Fam > > 2. Convert more carefully, making sure that packets are actually > dropped and QEMU does not spin on a readable fd. > > I prefer #1 because it's easier to check that behavior is still correct. > It also minimizes queuing inside QEMU. > > Stefan
