The patch titled
taskstats: add context-switch counters
has been added to the -mm tree. Its filename is
taskstats-add-context-switch-counters.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: taskstats: add context-switch counters
From: Maxim Uvarov <muvarov@xxxxxxxxxxxxx>
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.
Signed-off-by: Maxim Uvarov <muvarov@xxxxxxxxxxxxx>
Cc: Shailabh Nagar <nagar@xxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: Jay Lan <jlan@xxxxxxxxxxxx>
Cc: Jonathan Lim <jlim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/accounting/getdelays.c | 19 ++++++++++++++--
Documentation/accounting/taskstats-struct.txt | 6 +++++
fs/proc/array.c | 8 ++++++
include/linux/taskstats.h | 5 +++-
kernel/taskstats.c | 4 +++
5 files changed, 39 insertions(+), 3 deletions(-)
diff -puN Documentation/accounting/getdelays.c~taskstats-add-context-switch-counters Documentation/accounting/getdelays.c
--- a/Documentation/accounting/getdelays.c~taskstats-add-context-switch-counters
+++ a/Documentation/accounting/getdelays.c
@@ -49,6 +49,7 @@ char name[100];
int dbg;
int print_delays;
int print_io_accounting;
+int print_task_context_switch_rates;
__u64 stime, utime;
#define PRINTF(fmt, arg...) { \
@@ -195,7 +196,7 @@ void print_delayacct(struct taskstats *t
"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 @@ void print_delayacct(struct taskstats *t
"count", "delay total", t->swapin_count, t->swapin_delay_total);
}
+void task_context_switch_rates(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 @@ int main(int argc, char *argv[])
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 @@ int main(int argc, char *argv[])
printf("printing IO accounting\n");
print_io_accounting = 1;
break;
+ case 'q':
+ printf("printing task/process context switch rates\n");
+ print_task_context_switch_rates = 1;
+ break;
case 'w':
logfile = strdup(optarg);
printf("write to file %s\n", logfile);
@@ -389,6 +402,8 @@ int main(int argc, char *argv[])
print_delayacct((struct taskstats *) NLA_DATA(na));
if (print_io_accounting)
print_ioacct((struct taskstats *) NLA_DATA(na));
+ if (print_task_context_switch_rates)
+ task_context_switch_rates((struct taskstats *) NLA_DATA(na));
if (fd) {
if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
err(1,"write error\n");
diff -puN Documentation/accounting/taskstats-struct.txt~taskstats-add-context-switch-counters Documentation/accounting/taskstats-struct.txt
--- a/Documentation/accounting/taskstats-struct.txt~taskstats-add-context-switch-counters
+++ a/Documentation/accounting/taskstats-struct.txt
@@ -22,6 +22,8 @@ There are three different groups of fiel
/* Extended accounting fields end */
Their values are collected if CONFIG_TASK_XACCT is set.
+4) Per-task and per-thread context switch rates statistics
+
Future extension should add fields to the end of the taskstats struct, and
should not change the relative position of each field within the struct.
@@ -158,4 +160,8 @@ struct taskstats {
/* Extended accounting fields end */
+4) Per-task and per-thread statistics
+ __u64 nvcsw; /* Context voluntary switch counter */
+ __u64 nivcsw; /* Context involuntary switch counter */
+
}
diff -puN fs/proc/array.c~taskstats-add-context-switch-counters fs/proc/array.c
--- a/fs/proc/array.c~taskstats-add-context-switch-counters
+++ a/fs/proc/array.c
@@ -290,6 +290,13 @@ static inline char *task_cap(struct task
cap_t(p->cap_permitted),
cap_t(p->cap_effective));
}
+static inline char *task_context_switch_rates(struct task_struct *p, char *buffer)
+{
+ return buffer + sprintf(buffer, "voluntary_ctxt_switches:\t%lu\n"
+ "nonvoluntary_ctxt_switches:\t%lu\n",
+ p->nvcsw,
+ p->nivcsw);
+}
int proc_pid_status(struct task_struct *task, char * buffer)
{
@@ -309,6 +316,7 @@ int proc_pid_status(struct task_struct *
#if defined(CONFIG_S390)
buffer = task_show_regs(task, buffer);
#endif
+ buffer = task_context_switch_rates(task, buffer);
return buffer - orig;
}
diff -puN include/linux/taskstats.h~taskstats-add-context-switch-counters include/linux/taskstats.h
--- a/include/linux/taskstats.h~taskstats-add-context-switch-counters
+++ a/include/linux/taskstats.h
@@ -31,7 +31,7 @@
*/
-#define TASKSTATS_VERSION 4
+#define TASKSTATS_VERSION 5
#define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN
* in linux/sched.h */
@@ -149,6 +149,9 @@ struct taskstats {
__u64 read_bytes; /* bytes of read I/O */
__u64 write_bytes; /* bytes of write I/O */
__u64 cancelled_write_bytes; /* bytes of cancelled write I/O */
+
+ __u64 nvcsw; /* voluntary_ctxt_switches */
+ __u64 nivcsw; /* nonvoluntary_ctxt_switches */
};
diff -puN kernel/taskstats.c~taskstats-add-context-switch-counters kernel/taskstats.c
--- a/kernel/taskstats.c~taskstats-add-context-switch-counters
+++ a/kernel/taskstats.c
@@ -196,6 +196,8 @@ static int fill_pid(pid_t pid, struct ta
/* fill in basic acct fields */
stats->version = TASKSTATS_VERSION;
+ stats->nvcsw = tsk->nvcsw;
+ stats->nivcsw = tsk->nivcsw;
bacct_add_tsk(stats, tsk);
/* fill in extended acct fields */
@@ -242,6 +244,8 @@ static int fill_tgid(pid_t tgid, struct
*/
delayacct_add_tsk(stats, tsk);
+ stats->nvcsw += tsk->nvcsw;
+ stats->nivcsw += tsk->nivcsw;
} while_each_thread(first, tsk);
unlock_task_sighand(first, &flags);
_
Patches currently in -mm which might be from muvarov@xxxxxxxxxxxxx are
taskstats-add-context-switch-counters.patch
taskstats-add-context-switch-counters-fix.patch
-
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