Re: [PATCH] sys_epoll system call interface to /dev/epoll

[Davide Libenzi <davidel@xmailserver.org>]

On Fri, 18 Oct 2002, Linus Torvalds wrote:

>
> On Fri, 18 Oct 2002, Hanna Linder wrote:
> >
> > 	You said earlier that you didn't like epoll being
> > in /dev. How about a system call interface instead? this
> > patch provides the skeleton for that system call. We
> > can have Davide's patch ported into it ASAP if you include
> > this by the freeze.
>
> I like it noticeably better as a system call, so it's maybe worth
> discussing. It's not going to happen before I leave (very early tomorrow
> morning), but if people involved agree on this and clean patches to
> actiually add the code (not just system call stubs) can be made..

Linus, yesterday I was sugesting Hanna to use most of the existing code
and to make :

int sys_epoll_create(int maxfds);

to actually return an fd. Basically during this function call the code
allocates a file*, initialize it, allocates a free fd, maps the file* to
the fd, creates the vma* for the shared events area between the kernel and
user space, maps allocated kernel pages to the vma*, install the vma* and
returns the fd. In this way we can avoid the sys_epoll_close() and close()
can be used. Also the task cleanup comes for free being linked to a file*.
In this way also users that are using /dev/epoll in the old way can
continue to use it, being the skeleton code the same.
Do I have to guess that you do not like this idea ?



- Davide