xnu-2050.7.9.tar.gz

[apple/xnu.git] / osfmk / kern / sched_fixedpriority.c

diff --git a/osfmk/kern/sched_fixedpriority.c b/osfmk/kern/sched_fixedpriority.c
index 1eca4aaacef8808e5151337ba95527788dca8f07..ccde4a094bd018ae5e92749bb3db8bc79a7f476e 100644 (file)
--- a/osfmk/kern/sched_fixedpriority.c
+++ b/osfmk/kern/sched_fixedpriority.c
@@ -551,9 +551,15 @@ static ast_t
 sched_fixedpriority_processor_csw_check(processor_t processor)
 {
        run_queue_t             runq;
-       
+       boolean_t               has_higher;
+
        runq = runq_for_processor(processor);
-       if (runq->highq > processor->current_pri) {
+       if (first_timeslice(processor)) {
+               has_higher = (runq->highq > processor->current_pri);
+       } else {
+               has_higher = (runq->highq >= processor->current_pri);
+       }
+       if (has_higher) {
                if (runq->urgency > 0)
                        return (AST_PREEMPT | AST_URGENT);
 
@@ -647,6 +653,61 @@ sched_fixedpriority_update_priority(thread_t       thread)
 
        }
        
+#if CONFIG_EMBEDDED
+       /* Check for pending throttle transitions, and safely switch queues */
+       if ((thread->sched_flags & TH_SFLAG_PENDING_THROTTLE_MASK) && (thread->bound_processor == PROCESSOR_NULL)) {
+                       boolean_t               removed = thread_run_queue_remove(thread);
+
+                       if (thread->sched_flags & TH_SFLAG_PENDING_THROTTLE_DEMOTION) {
+                               if (thread->sched_mode == TH_MODE_REALTIME) {
+                                       thread->saved_mode = thread->sched_mode;
+                                       thread->sched_mode = TH_MODE_TIMESHARE;
+
+                                       if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN)
+                                               sched_share_incr();
+                               } else {
+                                       /*
+                                        * It's possible that this is a realtime thread that has
+                                        * already tripped the failsafe, in which case it should not
+                                        * degrade further.
+                                        */
+                                       if (!(thread->sched_flags & TH_SFLAG_FAILSAFE)) {
+
+                                               thread->saved_mode = thread->sched_mode;
+
+                                               if (thread->sched_mode == TH_MODE_TIMESHARE) {
+                                                       thread->sched_mode = TH_MODE_FAIRSHARE;
+                                               }
+                                       }
+                               }
+                               thread->sched_flags |= TH_SFLAG_THROTTLED;
+
+                               KERNEL_DEBUG_CONSTANT(
+                                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_FAIRSHARE_ENTER) | DBG_FUNC_NONE, (uintptr_t)thread_tid(thread), 0xFFFFFFFF, 0, 0, 0);
+
+                       } else {
+                               if ((thread->sched_mode == TH_MODE_TIMESHARE)
+                                       && (thread->saved_mode == TH_MODE_REALTIME)) {
+                                       if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN)
+                                               sched_share_decr();
+                               }
+
+                               thread->sched_mode = thread->saved_mode;
+                               thread->saved_mode = TH_MODE_NONE;
+                               thread->sched_flags &= ~TH_SFLAG_THROTTLED;
+
+                               KERNEL_DEBUG_CONSTANT1(
+                                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_FAIRSHARE_EXIT) | DBG_FUNC_NONE, 0, 0, 0, 0, thread_tid(thread));
+
+                       }
+
+                       thread->sched_flags &= ~(TH_SFLAG_PENDING_THROTTLE_MASK);
+
+                       if (removed)
+                               thread_setrun(thread, SCHED_TAILQ);
+       }
+#endif
+
        /*
         *      Check for fail-safe release.
         */