davidxu at freebsd.org
Mon Oct 30 23:18:23 UTC 2006
On Tuesday 31 October 2006 02:23, gnn at freebsd.org wrote:
> > I will hack at kernel side, but who will hack userland utilities ?
> > e.g the /usr/bin/limits program.
> How hard is that to do? If it's "easy" then I can sign up to do that.
I think it is not hard, but I think one at least has to hack /usr/bin/limits,
sh and csh which are in our base system.
> > > > 2) Things can only be used by root:
> > > >
> > > > 2.1) the real-time scheduling options can only be used by root, e.g,
> > > > if you call pthread_attr_setschedpolicy() with parameter SCHED_FIFO
> > > > or SCHED_RR, the thread can only be created by root, normal user
> > > > will get EPERM errno. you can use it in libpthread, but it is not
> > > > real-time, it is a static priority scheduling in userland scheduler,
> > > > if you want to preemptable other threads or processes in the system
> > > > when playing real-time multimedia or military program, no way!
> > > >
> > > > 2.2) the real-time scheduling is not safe, it can deadlock itself and
> > > > the whole system if program behavors incorrectly, it should only be
> > > > used by trusted programs.
> > >
> > > Are these (can these be) documented in the man pages?
> > No, they are not documented.
> If these limitations will be there for a while can you update the man
> page? If you like I can review that change for correctness.
I will update them and make them reviewed.
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