Resolves: bz 449949

irqbalance.1

@@ -53,3 +53,17 @@ Same as --debug
 .TP
 .B IRQBALANCE_BANNED_CPUS
 Provides a mask of cpus which irqbalance should ignore and never assign interrupts to
+
+.SH "NOTES"
+The purpose of irqbalance is to distribute interrupts accross cpus in an smp
+system such that cache-domain affinity is maximized for each irq.  In other
+words, irqbalance tries to assign irqs to cpu cores such that each irq stands a
+greater chance of having its interrupt handler be in cache when the irq is
+asserted to the cpu.  This raises a few interesting cases in which the behavior
+of irqbalance may be non-intuitive.  Most notably, cases in which a system has
+only one cache domain.  Nominally these systems are only single cpu
+environments, but can also be found in multi-core environments in which the
+cores share an L2 cache.  In these situations irqbalance will exit immediately,
+since there is no work that irqbalance can do which will improve interrupt
+handling performance.  This is normal and not cause for concern.  For more
+information regarding irqbalance, please visit http://irqbalance.org/

irqbalance.spec

@@ -1,7 +1,7 @@
 Summary:        IRQ balancing daemon.
 Name:           irqbalance
 Version:        0.55 
-Release: 	9%{?dist}
+Release: 	10%{?dist}
 Epoch:		2	
 Group:          System Environment/Base
 License:        GPL/OSL
@@ -78,6 +78,9 @@ exit 0
 
 
 %changelog
+* Tue Jun 04 2008 Neil Horman <nhorman@redhat.com> - 2:0.55-10
+- Update man page to explain why irqbalance exits on single cache (bz 449949)
+
 * Tue Mar 18 2008 Neil Horman <nhorman@redhat.com> - 2:0.55-9
 - Rediff pid-file patch to not remove initial parse_cpu_tree (bz 433270)