- Use the correct test in the ipi bitmask handler for IPI_PREEMPT so that

   we actually issue preemptions.
 - Remove the #ifdef IPI_PREEMPTION so it is always compiled in.  Leave
   the option which optionally enables support in sched_4bsd.  sched_ule.c
   will soon use this functionality as a run time rather than compile time
   option.
 - Compare against the idlethread rather than the priority.  There are some
   idle prio tasks that we can preempt.

Discussed with:	ups
Tested on:	i386, amd64

1 files changed, 3 insertions, 9 deletions

diff --git a/sys/i386/i386/mp_machdep.c b/sys/i386/i386/mp_machdep.c
index 1933511..4cc5b73 100644
--- a/sys/i386/i386/mp_machdep.c
+++ b/sys/i386/i386/mp_machdep.c
@@ -163,9 +163,7 @@ static void	ipi_nmi_selected(u_int32_t cpus);
 
 #ifdef COUNT_IPIS
 /* Interrupt counts. */
-#ifdef IPI_PREEMPTION
 static u_long *ipi_preempt_counts[MAXCPU];
-#endif
 static u_long *ipi_ast_counts[MAXCPU];
 u_long *ipi_invltlb_counts[MAXCPU];
 u_long *ipi_invlrng_counts[MAXCPU];
@@ -1143,14 +1141,13 @@ ipi_bitmap_handler(struct trapframe frame)
 
 	ipi_bitmap = atomic_readandclear_int(&cpu_ipi_pending[cpu]);
 
-#ifdef IPI_PREEMPTION
-	if (ipi_bitmap & IPI_PREEMPT) {
+	if (ipi_bitmap & (1 << IPI_PREEMPT)) {
 #ifdef COUNT_IPIS
 		*ipi_preempt_counts[cpu]++;
 #endif
 		mtx_lock_spin(&sched_lock);
 		/* Don't preempt the idle thread */
-		if (curthread->td_priority <  PRI_MIN_IDLE) {
+		if (curthread != PCPU_GET(idlethread)) {
 			struct thread *running_thread = curthread;
 			if (running_thread->td_critnest > 1) 
 				running_thread->td_owepreempt = 1;
@@ -1159,9 +1156,8 @@ ipi_bitmap_handler(struct trapframe frame)
 		}
 		mtx_unlock_spin(&sched_lock);
 	}
-#endif
 
-	if (ipi_bitmap & IPI_AST) {
+	if (ipi_bitmap & (1 << IPI_AST)) {
 #ifdef COUNT_IPIS
 		*ipi_ast_counts[cpu]++;
 #endif
@@ -1514,10 +1510,8 @@ mp_ipi_intrcnt(void *dummy)
 		intrcnt_add(buf, &ipi_invlrng_counts[i]);
 		snprintf(buf, sizeof(buf), "cpu%d: invlpg", i);
 		intrcnt_add(buf, &ipi_invlpg_counts[i]);
-#ifdef IPI_PREEMPTION
 		snprintf(buf, sizeof(buf), "cpu%d: preempt", i);
 		intrcnt_add(buf, &ipi_preempt_counts[i]);
-#endif
 		snprintf(buf, sizeof(buf), "cpu%d: ast", i);
 		intrcnt_add(buf, &ipi_ast_counts[i]);
 		snprintf(buf, sizeof(buf), "cpu%d: rendezvous", i);