/*
***************************************************************************
- * Read interrupts statistics from /proc/stat.
- * Remember that this function is used by several sysstat commands!
+ * Read interrupts statistics from /proc/interrupts.
*
* IN:
* @st_irq Structure where stats will be saved.
- * @nr_alloc Number of structures allocated. Value is >= 1.
+ * @nr_alloc Number of CPU structures allocated. Value is >= 1.
+ * @nr_int Number of interrupts, including sum. value is >= 1.
*
* OUT:
* @st_irq Structure with statistics.
*
* RETURNS:
- * Number of interrupts read, or -1 if the buffer was too small and
- * needs to be reallocated.
+ * Highest CPU number for which stats have been successfully read (2 for CPU0,
+ * 3 for CPU 1, etc.) Same logic than for softnet statistics. This number will
+ * be saved in a->_nr0. See wrap_read_stat_irq().
+ * Returns 0 if no statistics have been read.
+ * Returns -1 if the buffer was too small and needs to be reallocated (we
+ * mean here, too small for all the CPU, not for the interrupts whose number
+ * is considered to be a constant. Remember that only the number of items is
+ * saved in file preceding each sample, not the number of sub-items).
***************************************************************************
*/
-__nr_t read_stat_irq(struct stats_irq *st_irq, __nr_t nr_alloc)
+__nr_t read_stat_irq(struct stats_irq *st_irq, __nr_t nr_alloc, __nr_t nr_int)
{
FILE *fp;
- struct stats_irq *st_irq_i;
- char line[8192];
- int i, pos;
- unsigned long long irq_nr;
- __nr_t irq_read = 0;
-
- if ((fp = fopen(STAT, "r")) == NULL)
- return 0;
+ struct stats_irq *st_cpuall_sum, *st_cpu_irq, *st_cpu_sum, *st_cpuall_irq;
+ char *line = NULL, *li;
+ int rc = 0, irq_read = 0;
+ int cpu, len;
+ int cpu_nr = nr_alloc - 1;
+ int *cpu_index = NULL, index = 0;
+ char *cp, *next;
+
+ if (!cpu_nr) {
+ /* We have only one proc and a non SMP kernel */
+ cpu_nr = 1;
+ }
+ SREALLOC(cpu_index, int, sizeof(int) * cpu_nr);
- while (fgets(line, sizeof(line), fp) != NULL) {
+ if ((fp = fopen(INTERRUPTS, "r")) != NULL) {
- if (!strncmp(line, "intr ", 5)) {
- /* Read total number of interrupts received since system boot */
- sscanf(line + 5, "%llu", &st_irq->irq_nr);
- pos = strcspn(line + 5, " ") + 5;
+ SREALLOC(line, char, INTERRUPTS_LINE + 11 * cpu_nr);
- irq_read++;
- if (nr_alloc == 1)
- /* We just want to read the total number of interrupts */
+ /*
+ * Parse header line to see which CPUs are online
+ */
+ while (fgets(line, INTERRUPTS_LINE + 11 * cpu_nr, fp) != NULL) {
+ next = line;
+ while (((cp = strstr(next, "CPU")) != NULL) && (index < cpu_nr)) {
+ cpu = strtol(cp + 3, &next, 10);
+ if (cpu + 2 > nr_alloc) {
+ rc = -1;
+ goto out;
+ }
+ cpu_index[index++] = cpu;
+ }
+ if (index)
+ /* Header line found */
break;
+ }
- do {
- i = sscanf(line + pos, " %llu", &irq_nr);
- if (i < 1)
- break;
+ st_cpuall_sum = st_irq;
+ /* Save name "sum" for total number of interrupts */
+ strcpy(st_cpuall_sum->irq_name, K_LOWERSUM);
- if (irq_read + 1 > nr_alloc) {
- irq_read = -1;
- break;
- }
- st_irq_i = st_irq + irq_read++;
- st_irq_i->irq_nr = irq_nr;
+ /* Parse each line of interrupts statistics data */
+ while ((fgets(line, INTERRUPTS_LINE + 11 * cpu_nr, fp) != NULL) &&
+ (irq_read < nr_int - 1)) {
- i = strcspn(line + pos + 1, " ");
- pos += i + 1;
- }
- while ((i > 0) && (pos < (sizeof(line) - 1)));
+ /* Skip over "<irq>:" */
+ if ((cp = strchr(line, ':')) == NULL)
+ /* Chr ':' not found */
+ continue;
+ cp++;
- break;
+ irq_read++;
+ st_cpuall_irq = st_irq + irq_read;
+
+ /* Remove possible heading spaces in interrupt's name... */
+ li = line;
+ while (*li == ' ')
+ li++;
+
+ len = strcspn(li, ":");
+ if (len >= MAX_SA_IRQ_LEN) {
+ len = MAX_SA_IRQ_LEN - 1;
+ }
+ /* ...then save its name */
+ strncpy(st_cpuall_irq->irq_name, li, len);
+ st_cpuall_irq->irq_name[len] = '\0';
+
+ /* For each interrupt: Get number received by each CPU */
+ for (cpu = 0; cpu < index; cpu++) {
+ st_cpu_sum = st_irq + (cpu_index[cpu] + 1) * nr_int;
+ st_cpu_irq = st_irq + (cpu_index[cpu] + 1) * nr_int + irq_read;
+ /*
+ * Interrupt name is saved only for CPU "all".
+ * Now save current interrupt value for current CPU
+ * and total number of interrupts received by current CPU
+ * and number of current interrupt received by all CPU.
+ */
+ st_cpu_irq->irq_nr = strtoul(cp, &next, 10);
+ st_cpuall_irq->irq_nr += st_cpu_irq->irq_nr;
+ st_cpu_sum->irq_nr += st_cpu_irq->irq_nr;
+ cp = next;
+ }
+ st_cpuall_sum->irq_nr += st_cpuall_irq->irq_nr;
}
+out:
+ free(line);
+ fclose(fp);
}
- fclose(fp);
- return irq_read;
+ if (index && !rc) {
+ rc = cpu_index[index - 1] + 2;
+ }
+
+ free(cpu_index);
+
+ return rc;
}
/*
projects / sysstat / commitdiff