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/
