taskstats: add context-switch counters
Make available to the user the following task and process performance
statistics:
* Involuntary Context Switches (task_struct->nivcsw)
* Voluntary Context Switches (task_struct->nvcsw)
Statistics information is available from:
1. taskstats interface (Documentation/accounting/)
2. /proc/PID/status (task only).
This data is useful for detecting hyperactivity patterns between processes.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Maxim Uvarov <muvarov@ru.mvista.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Jonathan Lim <jlim@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/accounting/getdelays.c b/Documentation/accounting/getdelays.c
index 71acc28..24c5aad 100644
--- a/Documentation/accounting/getdelays.c
+++ b/Documentation/accounting/getdelays.c
@@ -49,6 +49,7 @@
int dbg;
int print_delays;
int print_io_accounting;
+int print_task_context_switch_counts;
__u64 stime, utime;
#define PRINTF(fmt, arg...) { \
@@ -195,7 +196,7 @@
"IO %15s%15s\n"
" %15llu%15llu\n"
"MEM %15s%15s\n"
- " %15llu%15llu\n\n",
+ " %15llu%15llu\n"
"count", "real total", "virtual total", "delay total",
t->cpu_count, t->cpu_run_real_total, t->cpu_run_virtual_total,
t->cpu_delay_total,
@@ -204,6 +205,14 @@
"count", "delay total", t->swapin_count, t->swapin_delay_total);
}
+void task_context_switch_counts(struct taskstats *t)
+{
+ printf("\n\nTask %15s%15s\n"
+ " %15lu%15lu\n",
+ "voluntary", "nonvoluntary",
+ t->nvcsw, t->nivcsw);
+}
+
void print_ioacct(struct taskstats *t)
{
printf("%s: read=%llu, write=%llu, cancelled_write=%llu\n",
@@ -235,7 +244,7 @@
struct msgtemplate msg;
while (1) {
- c = getopt(argc, argv, "diw:r:m:t:p:vl");
+ c = getopt(argc, argv, "qdiw:r:m:t:p:vl");
if (c < 0)
break;
@@ -248,6 +257,10 @@
printf("printing IO accounting\n");
print_io_accounting = 1;
break;
+ case 'q':
+ printf("printing task/process context switch rates\n");
+ print_task_context_switch_counts = 1;
+ break;
case 'w':
logfile = strdup(optarg);
printf("write to file %s\n", logfile);
@@ -389,6 +402,8 @@
print_delayacct((struct taskstats *) NLA_DATA(na));
if (print_io_accounting)
print_ioacct((struct taskstats *) NLA_DATA(na));
+ if (print_task_context_switch_counts)
+ task_context_switch_counts((struct taskstats *) NLA_DATA(na));
if (fd) {
if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
err(1,"write error\n");