On Wed, 14 Feb 2007, Ingo Molnar wrote:
> yeah, that's another key thing. I do plan to provide a sys_upcall()
> syscall as well which calls a 5-parameter user-space function with a
> special stack. (it's like a lightweight signal/event handler, without
> any of the signal handler legacies and overhead - it's like a reverse
> system call - a "user call". Obviously pure userspace would never use
> sys_upcall(), unless as an act of sheer masochism.)
That is exactly what I described as clets. Instead of having complex jump
and condition interpreters on the kernel (on top of new syscalls to
modify/increment userspace variables), you just code it in C and you pass
the clet pointer to the kernel.
The upcall will setup a frame, execute the clet (where jump/conditions and
userspace variable changes happen in machine code - gcc is pretty good in
taking care of that for us) on its return, come back through a
sys_async_return, and go back to userspace.
- Davide
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
