Re: CVS commit: src/sys

[David Young <dyoung%pobox.com@localhost>]

On Sun, Feb 21, 2010 at 02:11:40AM +0000, Darran Hunt wrote:
> Module Name:  src
> Committed By: darran
> Date:         Sun Feb 21 02:11:40 UTC 2010
> 
> Modified Files:
>       src/sys/arch/i386/i386: trap.c vector.S
>       src/sys/kern: kern_lwp.c kern_proc.c kern_synch.c
>       src/sys/sys: lwp.h proc.h
> Added Files:
>       src/sys/sys: dtrace_bsd.h
> 
> Log Message:
> Add the DTrace hooks to the kernel (KDTRACE_HOOKS config option).
> DTrace adds a pointer to the lwp and proc structures which it uses to
> manage its state.  These are opaque from the kernel perspective to keep
> the kernel free of CDDL code. The state arenas are kmem_alloced and freed
> as proccesses and threads are created and destoyed.
> 
> Also add a check for trap06 (privileged/illegal instruction) so that
> DTrace can check for D scripts that may have triggered the trap so it
> can clean up after them and resume normal operation.
> 
> Ok with core@.

Wow, dtrace in the kernel!  This is exciting, thanks!

#ifdef makes kernel code hard to read.  Will you help arrest the
accretion of conditional compilation in kern_synch.c by consolidating
the conditional compilation in a static subroutine, for example:

static void
dtrace_vtime_switch(lwp_t *newl)
{
#ifdef KDTRACE_HOOKS
        /*
         * If DTrace has set the active vtime enum to anything
         * other than INACTIVE (0), then it should have set the
         * function to call.
         */
        if (dtrace_vtime_active) {
                (*dtrace_vtime_switch_func)(newl);
        }
#endif
}

Dave

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933