cvs commit: src/include Makefile spawn.h unistd.h src/lib/libc/gen Makefile.inc Symbol.map exec.3 exec.c posix_spawn.c

[John Baldwin]

On Tuesday 17 June 2008 11:15:20 am Maxim Sobolev wrote:
> Ed Schouten wrote:
> > * David Schultz <das at FreeBSD.ORG> wrote:
> >> I have no objections to this, but doesn't it defeat the whole
> >> purpose to implement posix_spawn() as a library function that just
> >> calls fork/exec?
> > 
> > When (if?) applications start to use posix_spawn() we may decide to move
> > it into the kernel at any time. It should be okay for now.
> 
> Are there any benefits of doing it in the kernel vs. doing it via fork+exec?

Speed.  You don't have to go mark all your pages as COW or some such only to 
turn around and throw the new mappings away and undo that.

-- 
John Baldwin