PSARC 2006/421 MPO Control And Observability Tools

4698370 Want tool for applying advice to affect memory allocation via madvise(3C)
5048416 Want to be able to observe lgroup memory placement via pmap(1)
5048789 Want tool for observing and affecting thread placement on lgroups
6424359 Want Perl interface to liblgrp(3LIB) library
6424363 Want tool for observing lgroup information
6424366 Want walkers for lgroup resources and lineage
6424384 Want ps(1) to be lgroup-aware
6424387 Want prstat(1M) to be lgroup-aware
6455612 DTrace proc provider should have inline for thread home lgroup
6455724 Want thread home lgroup visibility via /proc
6457390 threads should rehome to lgroup with same (or more affinity) than existing home lgroup
6457640 Want to expose lgroup load average scale to user-land

1 files changed, 24 insertions, 31 deletions

diff --git a/usr/src/uts/common/syscall/lgrpsys.c b/usr/src/uts/common/syscall/lgrpsys.c
index 09b9818ad6..17fa2e1ff9 100644
--- a/usr/src/uts/common/syscall/lgrpsys.c
+++ b/usr/src/uts/common/syscall/lgrpsys.c
@@ -2,9 +2,8 @@
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
- * Common Development and Distribution License, Version 1.0 only
- * (the "License").  You may not use this file except in compliance
- * with the License.
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
@@ -19,8 +18,9 @@
  *
  * CDDL HEADER END
  */
+
 /*
- * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -502,14 +502,13 @@ lgrp_affinity_best(kthread_t *t, struct cpupart *cpupart, lgrp_id_t start)
 	lgrpid = start;
 
 	/*
-	 * Begin with home as best lgroup if it's root or in this pset
-	 * Otherwise, use starting lgroup given above as best first.
+	 * Use starting lgroup given above as best first
 	 */
 	home = t->t_lpl->lpl_lgrpid;
-	if (LGRP_CPUS_IN_PART(home, cpupart))
-		best_lpl = &cpupart->cp_lgrploads[home];
-	else
+	if (LGRP_CPUS_IN_PART(lgrpid, cpupart))
 		best_lpl = &cpupart->cp_lgrploads[lgrpid];
+	else
+		best_lpl = &cpupart->cp_lgrploads[home];
 
 	best_aff = affs[best_lpl->lpl_lgrpid];
 
@@ -529,7 +528,7 @@ lgrp_affinity_best(kthread_t *t, struct cpupart *cpupart, lgrp_id_t start)
 		 */
 		lpl = &cpupart->cp_lgrploads[lgrpid];
 		if (affs[lgrpid] > best_aff) {
-			best_aff =  affs[lgrpid];
+			best_aff = affs[lgrpid];
 			best_lpl = lpl;
 		}
 
@@ -558,10 +557,11 @@ int
 lgrp_affinity_set_thread(kthread_t *t, lgrp_id_t lgrp, lgrp_affinity_t aff,
     lgrp_affinity_t **aff_buf)
 {
+	lgrp_affinity_t	*affs;
+	lgrp_id_t	best;
 	lpl_t		*best_lpl;
 	lgrp_id_t	home;
 	int		retval;
-	lgrp_id_t	start;
 
 	ASSERT(t != NULL);
 	ASSERT(MUTEX_HELD(&ttoproc(t)->p_lock));
@@ -589,33 +589,26 @@ lgrp_affinity_set_thread(kthread_t *t, lgrp_id_t lgrp, lgrp_affinity_t aff,
 		*aff_buf = NULL;
 	}
 
-	t->t_lgrp_affinity[lgrp] = aff;
-
-	/*
-	 * Select a new home if the thread's affinity is being cleared
-	 */
-	if (aff == LGRP_AFF_NONE) {
-		lgrp_move_thread(t, lgrp_choose(t, t->t_cpupart), 1);
-		thread_unlock(t);
-		return (retval);
-	}
+	affs = t->t_lgrp_affinity;
+	affs[lgrp] = aff;
 
 	/*
 	 * Find lgroup for which thread has most affinity,
-	 * starting after home
+	 * starting with lgroup for which affinity being set
 	 */
-	home = t->t_lpl->lpl_lgrpid;
-	start = home + 1;
-	if (start > lgrp_alloc_max)
-		start = 0;
-
-	best_lpl = lgrp_affinity_best(t, t->t_cpupart, start);
+	best_lpl = lgrp_affinity_best(t, t->t_cpupart, lgrp);
 
 	/*
-	 * Rehome if found lgroup with more affinity than home
+	 * Rehome if found lgroup with more affinity than home or lgroup for
+	 * which affinity is being set has same affinity as home
 	 */
-	if (best_lpl != NULL && best_lpl != t->t_lpl)
-		lgrp_move_thread(t, best_lpl, 1);
+	home = t->t_lpl->lpl_lgrpid;
+	if (best_lpl != NULL && best_lpl != t->t_lpl) {
+		best = best_lpl->lpl_lgrpid;
+		if (affs[best] > affs[home] || (affs[best] == affs[home] &&
+		    best == lgrp))
+			lgrp_move_thread(t, best_lpl, 1);
+	}
 
 	thread_unlock(t);