On Mon, Feb 22, 2010 at 11:31:31AM -0600, David Young wrote:
> 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 c...@.
>
> 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
How much code do the hooks add? If it is not very much, then just drop
the ifdefs completely..
