Messages in this thread | | | Date | Thu, 03 Sep 1998 16:58:02 +0200 | From | Joerg Pommnitz <> | Subject | Re: Differences between FreeBSD and Linux system call mechanism |
| |
Alexander Kjeldaas wrote: > > Doesn't this mean that it would be a good idea to let the kernel > implement system calls by mapping a page into user-space containing > the appropriate assembly instructions to most efficiently do the > system calls? > > astor
Probably not. In this case all you would effectively do is change the syscall interface from:
move parameters into registers int 0x80
to move parameters into registers jump to kernel entry instruction execute int 0x80 or sysenter
I don't have hard numbers, but it looks much slower to me, even if the new kernel entry instruction is a few cycles faster than int 0x80.
If something like this is implemented at all, it should be done in libc. glibc already has mechanisms in place to select CPU type optimized code at run time. It would probably be easy to use the same thing for system calls.
-- Regards Joerg GMD-IPSI, Dolivostr. 15, Zimmer 120, D-64293 Darmstadt +49-6151-869-786 (Phone), -818 (FAX)
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html
| |