Messages in this thread | | | Date | Tue, 25 Nov 2008 18:51:29 +0200 | From | Avi Kivity <> | Subject | Re: kvm aio wishlist |
| |
Ingo Molnar wrote: > >> Perhaps a variant of syslet, that is kernel-only, and does: >> >> - always allocate a new kernel stack at io_submit() time, but not a >> new thread >> > > such a N:M threading design is a loss - sooner or later we arrive to a > point where people actually start using it and then we want to > load-balance and schedule these entities. >
It's only N:M as long as its nonblocking. If it blocks it becomes 1:1 again. If it doesn't, it's probably faster to do things on the same cache as the caller.
> So i'd suggest the kthread based async engine i wrote for syslets. It > worked well and for kernel-only entities it schedules super-fast - it > can do up to 20 million events per second on a 16-way box i'm testing > on. The objections about syslets were not related to the scheduling of > it but were mostly about the userspace API/ABI: you dont have to use > that.
I'd love to have something :)
I guess any cache and latency considerations could be fixed if - we schedule a syslet for the first time when the thread that launched it exits to userspace - we queue it on the current cpu's runqueue
In that case, for the nonblocking case syslets and fibrils would have very similar performance.
-- error compiling committee.c: too many arguments to function
| |