X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/blobdiff_plain/d5d75bd0a34026ee4e67f21bdf3f3c62ecea6195..c9e9fb21c9ab82a8102647d67bcf956e0aba60af:/sys/kern/usched_dummy.c

diff --git a/sys/kern/usched_dummy.c b/sys/kern/usched_dummy.c
index 744c415a6e..fb22eb8dcb 100644
--- a/sys/kern/usched_dummy.c
+++ b/sys/kern/usched_dummy.c
@@ -31,7 +31,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * 
- * $DragonFly: src/sys/kern/usched_dummy.c,v 1.8 2007/04/30 07:18:54 dillon Exp $
+ * $DragonFly: src/sys/kern/usched_dummy.c,v 1.9 2008/04/21 15:24:46 dillon Exp $
  */
 
 #include <sys/param.h>
@@ -50,6 +50,7 @@
 
 #include <sys/thread2.h>
 #include <sys/spinlock2.h>
+#include <sys/mplock2.h>
 
 #define MAXPRI			128
 #define PRIBASE_REALTIME	0
@@ -71,6 +72,7 @@ static void dummy_recalculate_estcpu(struct lwp *lp);
 static void dummy_resetpriority(struct lwp *lp);
 static void dummy_forking(struct lwp *plp, struct lwp *lp);
 static void dummy_exiting(struct lwp *plp, struct lwp *lp);
+static void dummy_yield(struct lwp *lp);
 
 struct usched usched_dummy = {
 	{ NULL },
@@ -85,7 +87,8 @@ struct usched usched_dummy = {
 	dummy_resetpriority,
 	dummy_forking,
 	dummy_exiting,
-	NULL			/* setcpumask not supported */
+	NULL,			/* setcpumask not supported */
+	dummy_yield
 };
 
 struct usched_dummy_pcpu {
@@ -151,7 +154,8 @@ dummy_acquire_curproc(struct lwp *lp)
 	/*
 	 * If this cpu has no current thread, select ourself
 	 */
-	if (dd->uschedcp == NULL && TAILQ_EMPTY(&dummy_runq)) {
+	if (dd->uschedcp == lp ||
+	    (dd->uschedcp == NULL && TAILQ_EMPTY(&dummy_runq))) {
 		atomic_set_int(&dummy_curprocmask, gd->gd_cpumask);
 		dd->uschedcp = lp;
 		return;
@@ -361,6 +365,16 @@ dummy_recalculate_estcpu(struct lwp *lp)
 {
 }
 
+/*
+ * MPSAFE
+ */
+static
+void
+dummy_yield(struct lwp *lp)
+{
+	need_user_resched();
+}
+
 /*
  * DUMMY_RESETPRIORITY
  *
@@ -441,6 +455,8 @@ dummy_exiting(struct lwp *plp, struct lwp *lp)
  * is possible to deschedule an LWKT thread and then do some work before
  * switching away.  The thread can be rescheduled at any time, even before
  * we switch away.
+ *
+ * MPSAFE
  */
 #ifdef SMP
 
@@ -460,11 +476,6 @@ dummy_sched_thread(void *dummy)
     dd = &dummy_pcpu[cpuid];
     cpumask = 1 << cpuid;
 
-    /*
-     * Our Scheduler helper thread does not need to hold the MP lock
-     */
-    rel_mplock();
-
     for (;;) {
 	lwkt_deschedule_self(gd->gd_curthread);		/* interlock */
 	atomic_set_int(&dummy_rdyprocmask, cpumask);
@@ -526,7 +537,7 @@ dummy_sched_thread_cpu_init(void)
 	    kprintf(" %d", i);
 
 	lwkt_create(dummy_sched_thread, NULL, NULL, &dd->helper_thread, 
-		    TDF_STOPREQ, i, "dsched %d", i);
+		    TDF_STOPREQ | TDF_MPSAFE, i, "dsched %d", i);
 
 	/*
 	 * Allow user scheduling on the target cpu.  cpu #0 has already