Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 3 Feb 2014 14:06:04 -0800 | Subject | Re: [RFC PATCH 0/3] epoll: read(),write(),ioctl() interface |
| |
On Mon, Feb 3, 2014 at 1:51 PM, Eric Wong <normalperson@yhbt.net> wrote: > Andy Lutomirski <luto@amacapital.net> wrote: >> >> On 02/02/2014 06:17 PM, Nathaniel Yazdani wrote: >> > So are you saying that those features you mentioned are specifically sought >> > after for the kernel? If so I'd like to take a crack at some of them, >> > may as well >> > get some use out of my new knowledge of epoll internals :) >> >> If by "sought after", you mean "is there at least one epoll user who >> wants them", then yes :) >> >> I think that EPOLLET and EPOLLONESHOT are giant hacks, and that what >> everyone really wants is the ability to very efficiently toggle events >> on and off. The ability to do it simultaneously and inexpensively >> with epoll_wait would make it happen. > > Everybody using single-threaded epoll, you mean? I suppose there's > quite a few of those. > > I've pondered an epoll_xchg syscall which would behave like *BSD kevent > to satisfy single-threaded users, but never got around to it. All my > epoll uses are multithreaded w/ oneshot nowadays, so xchg would only > save one syscall per thread.
Even for multithreaded, the ability to rearm EPOLLONESHOT entries without extra syscalls would probably be useful.
--Andy
| |