mpstat: fix total par-cpu IRQ counts

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 33 insertions, 10 deletions

diff --git a/procps/mpstat.c b/procps/mpstat.c
index a1f3937c9..d19abee97 100644
--- a/procps/mpstat.c
+++ b/procps/mpstat.c
@@ -163,6 +163,7 @@ static double percent_value(data_t prev, data_t curr, data_t itv)
 
 static double hz_value(data_t prev, data_t curr, data_t itv)
 {
+        //bb_error_msg("curr:%lld prev:%lld G.hz:%u", curr, prev, G.hz);
         return ((double)overflow_safe_sub(prev, curr)) / itv * G.hz;
 }
 
@@ -413,6 +414,8 @@ static void write_stats_core(int prev, int current,
                                         continue;
                                 }
                         }
+                        //bb_error_msg("G.st_irq[%u][%u].irq_nr:%lld - G.st_irq[%u][%u].irq_nr:%lld",
+                        // current, cpu, G.st_irq[prev][cpu].irq_nr, prev, cpu, G.st_irq[current][cpu].irq_nr);
                         printf(" %9.2f\n", hz_value(G.st_irq[prev][cpu].irq_nr, G.st_irq[current][cpu].irq_nr, per_cpu_itv));
                 }
         }
@@ -523,16 +526,23 @@ static void get_cpu_statistics(struct stats_cpu *cpu, data_t *up, data_t *up0)
 static void get_irqs_from_stat(struct stats_irq *irq)
 {
         FILE *fp;
+        unsigned cpu;
         char buf[1024];
 
+        for (cpu = 1; cpu <= G.cpu_nr; cpu++) {
+                irq->irq_nr = 0;
+        }
+
         fp = fopen_for_read(PROCFS_STAT);
         if (!fp)
                 return;
 
         while (fgets(buf, sizeof(buf), fp)) {
-                if (strncmp(buf, "intr ", 5) == 0)
+                //bb_error_msg("/proc/stat:'%s'", buf);
+                if (strncmp(buf, "intr ", 5) == 0) {
                         /* Read total number of IRQs since system boot */
                         sscanf(buf + 5, "%"FMT_DATA"u", &irq->irq_nr);
+                }
         }
 
         fclose(fp);
@@ -554,12 +564,20 @@ static void get_irqs_from_interrupts(const char *fname,
         unsigned irq;
         int cpu_index[G.cpu_nr];
         int iindex;
-        int len, digit;
 
-        for (cpu = 1; cpu <= G.cpu_nr; cpu++) {
-                irq_i = &G.st_irq[current][cpu];
-                irq_i->irq_nr = 0;
-        }
+// Moved to get_irqs_from_stat(), which is called once, not twice,
+// unlike get_irqs_from_interrupts().
+// Otherwise reading of /proc/softirqs
+// was resetting counts to 0 after we painstakingly collected them from
+// /proc/interrupts. Which resulted in:
+// 01:32:47 PM  CPU    intr/s
+// 01:32:47 PM  all    591.47
+// 01:32:47 PM    0      0.00 <= ???
+// 01:32:47 PM    1      0.00 <= ???
+//      for (cpu = 1; cpu <= G.cpu_nr; cpu++) {
+//              G.st_irq[current][cpu].irq_nr = 0;
+//              //bb_error_msg("G.st_irq[%u][%u].irq_nr=0", current, cpu);
+//      }
 
         fp = fopen_for_read(fname);
         if (!fp)
@@ -587,11 +605,15 @@ static void get_irqs_from_interrupts(const char *fname,
         while (fgets(buf, buflen, fp)
          && irq < irqs_per_cpu
         ) {
+                int len;
+                char last_char;
                 char *cp;
-                /* Skip over "<irq>:" */
+
+                /* Skip over "IRQNAME:" */
                 cp = strchr(buf, ':');
                 if (!cp)
                         continue;
+                last_char = cp[-1];
 
                 ic = &per_cpu_stats[current][irq];
                 len = cp - buf;
@@ -600,7 +622,6 @@ static void get_irqs_from_interrupts(const char *fname,
                 }
                 safe_strncpy(ic->irq_name, buf, len + 1);
                 //bb_error_msg("%s: irq%d:'%s' buf:'%s'", fname, irq, ic->irq_name, buf);
-                digit = isdigit(buf[len - 1]);
                 cp++;
 
                 for (cpu = 0; cpu < iindex; cpu++) {
@@ -608,9 +629,11 @@ static void get_irqs_from_interrupts(const char *fname,
                         ic = &per_cpu_stats[current][cpu_index[cpu] * irqs_per_cpu + irq];
                         irq_i = &G.st_irq[current][cpu_index[cpu] + 1];
                         ic->interrupt = strtoul(cp, &next, 10);
-                        if (digit) {
-                                /* Do not count non-numerical IRQs */
+                        /* Count only numerical IRQs */
+                        if (isdigit(last_char)) {
                                 irq_i->irq_nr += ic->interrupt;
+                                //bb_error_msg("G.st_irq[%u][%u].irq_nr + %u = %lld",
+                                // current, cpu_index[cpu] + 1, ic->interrupt, irq_i->irq_nr);
                         }
                         cp = next;
                 }