Add the mp_watchdog hooks, although it locks up my SMP test box. It might

be useable to somebody.

sys/amd64/amd64/mp_machdep.c

@@ -29,6 +29,7 @@ __FBSDID("$FreeBSD$");
 
 #include "opt_cpu.h"
 #include "opt_kstack_pages.h"
+#include "opt_mp_watchdog.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -56,6 +57,7 @@ __FBSDID("$FreeBSD$");
 #include <machine/apicreg.h>
 #include <machine/clock.h>
 #include <machine/md_var.h>
+#include <machine/mp_watchdog.h>
 #include <machine/pcb.h>
 #include <machine/psl.h>
 #include <machine/smp.h>
@@ -1067,8 +1069,15 @@ int
 mp_grab_cpu_hlt(void)
 {
 	u_int mask = PCPU_GET(cpumask);
+#ifdef MP_WATCHDOG
+	u_int cpuid = PCPU_GET(cpuid);
+#endif
 	int retval;
 
+#ifdef MP_WATCHDOG
+	ap_watchdog(cpuid);
+#endif
+
 	retval = mask & hlt_cpus_mask;
 	while (mask & hlt_cpus_mask)
 		__asm __volatile("sti; hlt" : : : "memory");

sys/conf/files.amd64

@@ -79,6 +79,7 @@ amd64/amd64/locore.S		standard	no-obj
 amd64/amd64/machdep.c		standard
 amd64/amd64/mem.c		optional	mem
 amd64/amd64/mp_machdep.c	optional	smp
+amd64/amd64/mp_watchdog.c	optional	mp_watchdog smp
 amd64/amd64/mpboot.S		optional	smp
 amd64/amd64/mptable.c		optional	mptable
 amd64/amd64/mptable_pci.c	optional	mptable pci

sys/conf/options.amd64

@@ -6,6 +6,7 @@ AUTO_EOI_2		opt_auto_eoi.h
 MAXMEM
 PERFMON			opt_perfmon.h
 PMAP_SHPGPERPROC	opt_pmap.h
+MP_WATCHDOG		opt_mp_watchdog.h
 
 # Options for emulators.  These should only be used at config time, so
 # they are handled like options for static filesystems