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Date:      Tue, 3 Nov 2009 16:46:52 +0000 (UTC)
From:      Attilio Rao <attilio@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r198854 - in head/sys: kern sys vm
Message-ID:  <200911031646.nA3GkqB4096838@svn.freebsd.org>
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Author: attilio
Date: Tue Nov  3 16:46:52 2009
New Revision: 198854
URL: http://svn.freebsd.org/changeset/base/198854

Log:
  Split P_NOLOAD into a per-thread flag (TDF_NOLOAD).
  This improvements aims for avoiding further cache-misses in scheduler
  specific functions which need to keep track of average thread running
  time and further locking in places setting for this flag.
  
  Reported by:	jeff (originally), kris (currently)
  Reviewed by:	jhb
  Tested by:	Giuseppe Cocomazzi <sbudella at email dot it>

Modified:
  head/sys/kern/kern_idle.c
  head/sys/kern/kern_intr.c
  head/sys/kern/sched_4bsd.c
  head/sys/kern/sched_ule.c
  head/sys/sys/proc.h
  head/sys/vm/vm_zeroidle.c

Modified: head/sys/kern/kern_idle.c
==============================================================================
--- head/sys/kern/kern_idle.c	Tue Nov  3 12:52:35 2009	(r198853)
+++ head/sys/kern/kern_idle.c	Tue Nov  3 16:46:52 2009	(r198854)
@@ -74,10 +74,9 @@ idle_setup(void *dummy)
 		if (error)
 			panic("idle_setup: kproc_create error %d\n", error);
 
-		p->p_flag |= P_NOLOAD;
 		thread_lock(td);
 		TD_SET_CAN_RUN(td);
-		td->td_flags |= TDF_IDLETD;
+		td->td_flags |= TDF_IDLETD | TDF_NOLOAD;
 		sched_class(td, PRI_IDLE);
 		sched_prio(td, PRI_MAX_IDLE);
 		thread_unlock(td);

Modified: head/sys/kern/kern_intr.c
==============================================================================
--- head/sys/kern/kern_intr.c	Tue Nov  3 12:52:35 2009	(r198853)
+++ head/sys/kern/kern_intr.c	Tue Nov  3 16:46:52 2009	(r198854)
@@ -1061,6 +1061,7 @@ int
 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
 	    void *arg, int pri, enum intr_type flags, void **cookiep)
 {
+	struct thread *td;
 	struct intr_event *ie;
 	int error;
 
@@ -1085,11 +1086,10 @@ swi_add(struct intr_event **eventp, cons
 	if (error)
 		return (error);
 	if (pri == SWI_CLOCK) {
-		struct proc *p;
-		p = ie->ie_thread->it_thread->td_proc;
-		PROC_LOCK(p);
-		p->p_flag |= P_NOLOAD;
-		PROC_UNLOCK(p);
+		td = ie->ie_thread->it_thread;
+		thread_lock(td);
+		td->td_flags |= TDF_NOLOAD;
+		thread_unlock(td);
 	}
 	return (0);
 }

Modified: head/sys/kern/sched_4bsd.c
==============================================================================
--- head/sys/kern/sched_4bsd.c	Tue Nov  3 12:52:35 2009	(r198853)
+++ head/sys/kern/sched_4bsd.c	Tue Nov  3 16:46:52 2009	(r198854)
@@ -728,10 +728,10 @@ sched_exit_thread(struct thread *td, str
 	thread_lock(td);
 	td->td_estcpu = ESTCPULIM(td->td_estcpu + child->td_estcpu);
 	thread_unlock(td);
-	mtx_lock_spin(&sched_lock);
-	if ((child->td_proc->p_flag & P_NOLOAD) == 0)
+	thread_lock(child);
+	if ((child->td_flags & TDF_NOLOAD) == 0)
 		sched_load_rem();
-	mtx_unlock_spin(&sched_lock);
+	thread_unlock(child);
 }
 
 void
@@ -937,7 +937,7 @@ sched_switch(struct thread *td, struct t
 		thread_unlock(td);
 	}
 
-	if ((p->p_flag & P_NOLOAD) == 0)
+	if ((td->td_flags & TDF_NOLOAD) == 0)
 		sched_load_rem();
 
 	if (newtd)
@@ -980,7 +980,7 @@ sched_switch(struct thread *td, struct t
 			("trying to run inhibited thread"));
 		newtd->td_flags |= TDF_DIDRUN;
         	TD_SET_RUNNING(newtd);
-		if ((newtd->td_proc->p_flag & P_NOLOAD) == 0)
+		if ((newtd->td_flags & TDF_NOLOAD) == 0)
 			sched_load_add();
 	} else {
 		newtd = choosethread();
@@ -1289,7 +1289,7 @@ sched_add(struct thread *td, int flags)
 		}
 	}
 
-	if ((td->td_proc->p_flag & P_NOLOAD) == 0)
+	if ((td->td_flags & TDF_NOLOAD) == 0)
 		sched_load_add();
 	runq_add(ts->ts_runq, td, flags);
 	if (cpu != NOCPU)
@@ -1338,7 +1338,7 @@ sched_add(struct thread *td, int flags)
 		if (maybe_preempt(td))
 			return;
 	}
-	if ((td->td_proc->p_flag & P_NOLOAD) == 0)
+	if ((td->td_flags & TDF_NOLOAD) == 0)
 		sched_load_add();
 	runq_add(ts->ts_runq, td, flags);
 	maybe_resched(td);
@@ -1360,7 +1360,7 @@ sched_rem(struct thread *td)
 	    "prio:%d", td->td_priority, KTR_ATTR_LINKED,
 	    sched_tdname(curthread));
 
-	if ((td->td_proc->p_flag & P_NOLOAD) == 0)
+	if ((td->td_flags & TDF_NOLOAD) == 0)
 		sched_load_rem();
 #ifdef SMP
 	if (ts->ts_runq != &runq)

Modified: head/sys/kern/sched_ule.c
==============================================================================
--- head/sys/kern/sched_ule.c	Tue Nov  3 12:52:35 2009	(r198853)
+++ head/sys/kern/sched_ule.c	Tue Nov  3 16:46:52 2009	(r198854)
@@ -495,7 +495,7 @@ tdq_load_add(struct tdq *tdq, struct thr
 	THREAD_LOCK_ASSERT(td, MA_OWNED);
 
 	tdq->tdq_load++;
-	if ((td->td_proc->p_flag & P_NOLOAD) == 0)
+	if ((td->td_flags & TDF_NOLOAD) == 0)
 		tdq->tdq_sysload++;
 	KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load);
 }
@@ -514,7 +514,7 @@ tdq_load_rem(struct tdq *tdq, struct thr
 	    ("tdq_load_rem: Removing with 0 load on queue %d", TDQ_ID(tdq)));
 
 	tdq->tdq_load--;
-	if ((td->td_proc->p_flag & P_NOLOAD) == 0)
+	if ((td->td_flags & TDF_NOLOAD) == 0)
 		tdq->tdq_sysload--;
 	KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load);
 }

Modified: head/sys/sys/proc.h
==============================================================================
--- head/sys/sys/proc.h	Tue Nov  3 12:52:35 2009	(r198853)
+++ head/sys/sys/proc.h	Tue Nov  3 16:46:52 2009	(r198854)
@@ -322,7 +322,7 @@ do {									\
 #define	TDF_NEEDSUSPCHK	0x00008000 /* Thread may need to suspend. */
 #define	TDF_NEEDRESCHED	0x00010000 /* Thread needs to yield. */
 #define	TDF_NEEDSIGCHK	0x00020000 /* Thread may need signal delivery. */
-#define	TDF_UNUSED18	0x00040000 /* --available-- */
+#define	TDF_NOLOAD	0x00040000 /* Ignore during load avg calculations. */
 #define	TDF_UNUSED19	0x00080000 /* Thread is sleeping on a umtx. */
 #define	TDF_THRWAKEUP	0x00100000 /* Libthr thread must not suspend itself. */
 #define	TDF_UNUSED21	0x00200000 /* --available-- */
@@ -558,7 +558,7 @@ struct proc {
 #define	P_ADVLOCK	0x00001	/* Process may hold a POSIX advisory lock. */
 #define	P_CONTROLT	0x00002	/* Has a controlling terminal. */
 #define	P_KTHREAD	0x00004	/* Kernel thread (*). */
-#define	P_NOLOAD	0x00008	/* Ignore during load avg calculations. */
+#define	P_UNUSED0	0x00008	/* available. */
 #define	P_PPWAIT	0x00010	/* Parent is waiting for child to exec/exit. */
 #define	P_PROFIL	0x00020	/* Has started profiling. */
 #define	P_STOPPROF	0x00040	/* Has thread requesting to stop profiling. */

Modified: head/sys/vm/vm_zeroidle.c
==============================================================================
--- head/sys/vm/vm_zeroidle.c	Tue Nov  3 12:52:35 2009	(r198853)
+++ head/sys/vm/vm_zeroidle.c	Tue Nov  3 16:46:52 2009	(r198854)
@@ -139,26 +139,21 @@ vm_pagezero(void __unused *arg)
 	}
 }
 
-static struct proc *pagezero_proc;
-
 static void
 pagezero_start(void __unused *arg)
 {
 	int error;
+	struct proc *p;
 	struct thread *td;
 
-	error = kproc_create(vm_pagezero, NULL, &pagezero_proc, RFSTOPPED, 0,
-	    "pagezero");
+	error = kproc_create(vm_pagezero, NULL, &p, RFSTOPPED, 0, "pagezero");
 	if (error)
 		panic("pagezero_start: error %d\n", error);
-	/*
-	 * We're an idle task, don't count us in the load.
-	 */
-	PROC_LOCK(pagezero_proc);
-	pagezero_proc->p_flag |= P_NOLOAD;
-	PROC_UNLOCK(pagezero_proc);
-	td = FIRST_THREAD_IN_PROC(pagezero_proc);
+	td = FIRST_THREAD_IN_PROC(p);
 	thread_lock(td);
+
+	/* We're an idle task, don't count us in the load. */
+	td->td_flags |= TDF_NOLOAD;
 	sched_class(td, PRI_IDLE);
 	sched_prio(td, PRI_MAX_IDLE);
 	sched_add(td, SRQ_BORING);

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