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Date:      Thu, 16 Feb 2017 21:18:31 +0000 (UTC)
From:      Ryan Stone <rstone@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r313824 - head/sys/kern
Message-ID:  <201702162118.v1GLIVsq026589@repo.freebsd.org>
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Author: rstone
Date: Thu Feb 16 21:18:31 2017
New Revision: 313824
URL: https://svnweb.freebsd.org/changeset/base/313824

Log:
  Revert r313814 and r313816
  
  Something evidently got mangled in my git tree in between testing and
  review, as an old and broken version of the patch was apparently submitted
  to svn.  Revert this while I work out what went wrong.
  
  Reported by:	tuexen
  Pointy hat to:	rstone

Modified:
  head/sys/kern/sched_4bsd.c
  head/sys/kern/sched_ule.c

Modified: head/sys/kern/sched_4bsd.c
==============================================================================
--- head/sys/kern/sched_4bsd.c	Thu Feb 16 21:03:43 2017	(r313823)
+++ head/sys/kern/sched_4bsd.c	Thu Feb 16 21:18:31 2017	(r313824)
@@ -816,12 +816,7 @@ sched_class(struct thread *td, int class
 static void
 sched_priority(struct thread *td, u_char prio)
 {
-	struct thread *newtd;
-	struct runq *rq;
-	u_char orig_pri;
-#ifdef SMP
-	struct thread *cputd;
-#endif
+
 
 	KTR_POINT3(KTR_SCHED, "thread", sched_tdname(td), "priority change",
 	    "prio:%d", td->td_priority, "new prio:%d", prio, KTR_ATTR_LINKED,
@@ -837,43 +832,10 @@ sched_priority(struct thread *td, u_char
 	THREAD_LOCK_ASSERT(td, MA_OWNED);
 	if (td->td_priority == prio)
 		return;
-	orig_pri = td->td_priority;
 	td->td_priority = prio;
 	if (TD_ON_RUNQ(td) && td->td_rqindex != (prio / RQ_PPQ)) {
 		sched_rem(td);
 		sched_add(td, SRQ_BORING);
-	} else if (orig_pri < prio && TD_IS_RUNNING(td)) {
-		/*
-		 * If we have decreased the priority of a running thread, we
-		 * have to check if it should be preempted.
-		 */
-		rq = &runq;
-		newtd = runq_choose(&runq);
-#ifdef SMP
-		cputd = runq_choose(&runq_pcpu[td->td_oncpu]);
-		if (newtd == NULL ||
-		    (cputd != NULL && cputd->td_priority < td->td_priority))
-			newtd = cputd;
-#endif
-
-		if (newtd != NULL && newtd->td_priority < prio
-#ifndef FULL_PREEMPTION
-		    && (newtd->td_priority <= PRI_MAX_ITHD ||
-		        prio >= PRI_MIN_IDLE))
-#endif
-		) {
-			if (td == curthread)
-				/*
-				 * Don't reschedule the thread here as it may
-				 * be losing priority because it has released a
-				 * mutex, and in that case we need it to finish
-				 * releasing the lock before it gets preempted.
-				 */
-				td->td_owepreempt = 1;
-			else
-				kick_other_cpu(newtd->td_priority,
-				    td->td_oncpu);
-		}
 	}
 }
 

Modified: head/sys/kern/sched_ule.c
==============================================================================
--- head/sys/kern/sched_ule.c	Thu Feb 16 21:03:43 2017	(r313823)
+++ head/sys/kern/sched_ule.c	Thu Feb 16 21:18:31 2017	(r313824)
@@ -319,7 +319,7 @@ static void tdq_add(struct tdq *, struct
 #ifdef SMP
 static int tdq_move(struct tdq *, struct tdq *);
 static int tdq_idled(struct tdq *);
-static void tdq_notify(struct tdq *, int);
+static void tdq_notify(struct tdq *, struct thread *);
 static struct thread *tdq_steal(struct tdq *, int);
 static struct thread *runq_steal(struct runq *, int);
 static int sched_pickcpu(struct thread *, int);
@@ -1040,14 +1040,16 @@ tdq_idled(struct tdq *tdq)
  * Notify a remote cpu of new work.  Sends an IPI if criteria are met.
  */
 static void
-tdq_notify(struct tdq *tdq, int pri)
+tdq_notify(struct tdq *tdq, struct thread *td)
 {
 	struct thread *ctd;
+	int pri;
 	int cpu;
 
 	if (tdq->tdq_ipipending)
 		return;
-	cpu = TDQ_ID(tdq);
+	cpu = td_get_sched(td)->ts_cpu;
+	pri = td->td_priority;
 	ctd = pcpu_find(cpu)->pc_curthread;
 	if (!sched_shouldpreempt(pri, ctd->td_priority, 1))
 		return;
@@ -1673,22 +1675,6 @@ sched_pctcpu_update(struct td_sched *ts,
 	ts->ts_ltick = t;
 }
 
-static void
-sched_check_preempt(struct tdq *tdq, struct thread *td)
-{
-
-	KASSERT(TD_IS_RUNNING(td), ("thread is not running"));
-	TDQ_LOCK_ASSERT(tdq, MA_OWNED);
-	KASSERT(tdq == TDQ_CPU(td->td_sched->ts_cpu),
-	    ("tdq does not contain td"));
-
-	if (tdq == TDQ_SELF()) {
-		if (sched_shouldpreempt(tdq->tdq_lowpri, td->td_priority, 0))
-			td->td_owepreempt = 1;
-	} else
-		tdq_notify(tdq, tdq->tdq_lowpri);
-}
-
 /*
  * Adjust the priority of a thread.  Move it to the appropriate run-queue
  * if necessary.  This is the back-end for several priority related
@@ -1740,9 +1726,6 @@ sched_thread_priority(struct thread *td,
 			tdq->tdq_lowpri = prio;
 		else if (tdq->tdq_lowpri == oldpri)
 			tdq_setlowpri(tdq, td);
-
-		if (oldpri < prio)
-			sched_check_preempt(tdq, td);
 		return;
 	}
 	td->td_priority = prio;
@@ -1871,7 +1854,7 @@ sched_switch_migrate(struct tdq *tdq, st
 	 */
 	tdq_lock_pair(tdn, tdq);
 	tdq_add(tdn, td, flags);
-	tdq_notify(tdn, td->td_priority);
+	tdq_notify(tdn, td);
 	TDQ_UNLOCK(tdn);
 	spinlock_exit();
 #endif
@@ -2446,7 +2429,7 @@ sched_add(struct thread *td, int flags)
 	tdq = sched_setcpu(td, cpu, flags);
 	tdq_add(tdq, td, flags);
 	if (cpu != PCPU_GET(cpuid)) {
-		tdq_notify(tdq, td->td_priority);
+		tdq_notify(tdq, td);
 		return;
 	}
 #else

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