diff -up sysstat-9.0.6.1/mpstat.c.tl sysstat-9.0.6.1/mpstat.c

--- sysstat-9.0.6.1/mpstat.c.tl	2009-09-12 20:59:04.000000000 +0200

+++ sysstat-9.0.6.1/mpstat.c	2010-04-19 10:42:01.000000000 +0200

@@ -272,10 +272,21 @@ void write_stats_core(int prev, int curr

 			/* Recalculate itv for current proc */

 			pc_itv = get_per_cpu_interval(scc, scp);

-			if (!pc_itv) {

-				/* Current CPU is offline */

+			/* if the CPU is offline it is omited from /proc/stat

+			   so the sum of all values is zero */

+			if ((scc->cpu_user    + scc->cpu_nice   + scc->cpu_sys   +

+			     scc->cpu_iowait  + scc->cpu_idle   + scc->cpu_steal +

+			     scc->cpu_hardirq + scc->cpu_softirq) == 0) {

 				printf("    0.00    0.00    0.00    0.00    0.00    0.00"

 				       "    0.00    0.00    0.00\n");

+				continue;

+			}

+

+			/* if the CPU is tickless  then

+			  there is no change in CPU values but the sum of values is not null */

+			if (!pc_itv) {

+				printf("    0.00    0.00    0.00    0.00    0.00    0.00"

+				       "    0.00    0.00  100.00\n");

 			}

 			else {

 				printf("  %6.2f  %6.2f  %6.2f  %6.2f  %6.2f  %6.2f"

@@ -643,6 +654,14 @@ void rw_mpstat_loop(int dis_hdr, int row

 			scc = st_cpu[curr]  + cpu;

 			scp = st_cpu[!curr] + cpu;

 			*scc = *scp;

+			scc->cpu_user = 0;

+			scc->cpu_nice = 0;

+			scc->cpu_sys = 0;

+			scc->cpu_iowait = 0;

+			scc->cpu_idle = 0;

+			scc->cpu_steal = 0;

+			scc->cpu_hardirq = 0;

+			scc->cpu_softirq = 0;

 		}

 		/* Get time */