Re: [take21 0/4] kevent: Generic event handling mechanism.

Jeff Garzik
2006-11-07T12:32:33Z

Evgeniy Polyakov wrote:
> Mmap ring buffer implementation was stopped by Andrew Morton and Ulrich
> Drepper, process' memory is used instead. copy_to_user() is slower (and
> some times noticebly), but there are major advantages of such approach.

hmmmm. I say there are advantages to both.

Perhaps create a "kevent_direct_limit" resource limit for each thread.
By default, each thread could mmap $n pinned pagecache pages. Sysadmin
can tune certain app resource limits to permit more.

I would think that retaining the option to avoid copy_to_user()
-somehow- in -some- cases would be wise.

Jeff