Albert Cahalan wrote: > On Mon, Jul 5, 2010 at 12:10 AM, H. Peter Anvin <hpa@xxxxxxxxx> wrote: >> On 07/04/2010 04:39 PM, Matt Helsley wrote: >>>> 1. can you implement it for i386 (register starved) using eclone? >>> That's a very good question. I'm going to punt on a direct answer for >>> now. Instead, I wonder if it's even worth enabling vfork through eclone. >>> vfork is rarely used, is supported by the "old" clone syscall, and any >>> old code adapted to use eclone for vfork would need significant >>> changes because of vfork's specialness. (A consequence of the way vfork >>> borrows page tables and must avoid clobbering parent's registers..) >> vfork is its own system call for a reason. We used to do it with >> sys_clone, and it turned out to be a mess. Doing it in a separate >> system call -- even though the internals are largely the same -- is cleaner. > > That's interesting; only ia64 and xtensa still do vfork via clone. > I remember sys_vfork being purely i386. > > I guess we need an evfork then. We're slowly gaining all sorts > of functionality (various clone flags) that is inaccessible when > there is a need for vfork behavior. For the record, as far as I can tell, we don't need evfork() for checkpoint-restart. So you'd need to come up with other use cases. Oren. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
