cvs commit: src/sys/kern sys_process.c syscalls.master

[John Baldwin]

On Monday 15 March 2004 02:21 pm, Ken Smith wrote:
> On Mon, Mar 15, 2004 at 08:08:53PM +0100, Wilko Bulte wrote:
> > On Mon, Mar 15, 2004 at 10:48:28AM -0800, John Baldwin wrote:
> > > jhb         2004/03/15 10:48:28 PST
> > >
> > >   FreeBSD src repository
> > >
> > >   Modified files:
> > >     sys/kern             sys_process.c syscalls.master
> > >   Log:
> > >   Drop the proc lock around calls to the MD functions
> > > ptrace_single_step(), ptrace_set_pc(), and cpu_ptrace() so that those
> > > functions are free to acquire Giant, sleep, etc.  We already do a
> > > PHOLD/PRELE around them so that it is safe to sleep inside of these
> > > routines if necessary.  This allows ptrace() to be marked MP safe again
> > > as it no longer triggers lock order reversals on Alpha.
> >
> > Someone with a SMP alpha box might also want to give this a spin I
> > suppose.
>
> beast (alpha ref machine in the cluster) has dual processors, if something
> special needs to be done to test this we could arrange something.

You would need to dink with gdb (setting breakpoints, detach/attach, etc.) on 
a kernel with WITNESS turned on and see if it breaks or whines.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org