Patchwork [2/5] powerpc/numa: Check for all VPHN changes

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Submitter Anton Blanchard
Date Jan. 29, 2011, 10:26 p.m.
Message ID <20110130092619.7e414259@kryten>
Download mbox | patch
Permalink /patch/80979/
State Accepted, archived
Commit d69043e8069f493ebee9472bcc78b3f54c5c27d9
Delegated to: Benjamin Herrenschmidt
Headers show

Comments

Anton Blanchard - Jan. 29, 2011, 10:26 p.m.
The hypervisor uses unsigned 1 byte counters to signal topology changes to
the OS. Since they can wrap we need to check for any difference, not just if
the hypervisor count is greater than the previous count.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Patch

Index: linux-2.6/arch/powerpc/mm/numa.c
===================================================================
--- linux-2.6.orig/arch/powerpc/mm/numa.c	2011-01-29 11:16:56.741843175 +1100
+++ linux-2.6/arch/powerpc/mm/numa.c	2011-01-29 12:44:42.059356526 +1100
@@ -1342,7 +1342,7 @@  static int update_cpu_associativity_chan
 		volatile u8 *hypervisor_counts = lppaca[cpu].vphn_assoc_counts;
 
 		for (i = 0; i < distance_ref_points_depth; i++) {
-			if (hypervisor_counts[i] > counts[i]) {
+			if (hypervisor_counts[i] != counts[i]) {
 				counts[i] = hypervisor_counts[i];
 				changed = 1;
 			}