Documentation: fix getdelays.c example -l option and segv

Fix a couple of minor issues with the getdelays.c example code.

Quoted 1 line

Fix a couple of minor issues with the getdelays.c example code.

What issues?

Fix a couple of minor issues with the getdelays.c example code.

Signed-off-by Michael Neuling <[email protected]>

---
 Documentation/accounting/getdelays.c |   21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

Index: linux-2.6-ozlabs/Documentation/accounting/getdelays.c
===================================================================

Documentation/accounting/getdelays.c +9 -9

 	       "count", "real total", "virtual total", "delay total",
 	       t->cpu_count, t->cpu_run_real_total, t->cpu_run_virtual_total,
 	       t->cpu_delay_total,

@@ -335,17 +335,17 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if (tid) {
-		rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
-			      cmd_type, &tid, sizeof(__u32));
-		PRINTF("Sent pid/tgid, retval %d\n", rc);
-		if (rc < 0) {
-			fprintf(stderr, "error sending tid/tgid cmd\n");
-			goto done;
+	do {
+		if (tid) {
+			rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
+				      cmd_type, &tid, sizeof(__u32));
+			PRINTF("Sent pid/tgid, retval %d\n", rc);
+			if (rc < 0) {
+				fprintf(stderr, "error sending tid/tgid cmd\n");
+				goto done;
+			}
 		}
-	}
 
-	do {
 		int i;
 
 		rep_len = recv(nl_sd, &msg, sizeof(msg), 0);

Documentation/accounting/getdelays.c +0 -0

 	} while (loop);
 done:
 	if (maskset) {

Quoted 7 lines · Michael Neuling

Fix a couple of minor issues with the getdelays.c example code.

Signed-off-by Michael Neuling <[email protected]>

---
 Documentation/accounting/getdelays.c |   21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

Documentation/accounting/getdelays.c void print_delayacct(struct taskstats *t · line 199

Quoted 10 lines

Index: linux-2.6-ozlabs/Documentation/accounting/getdelays.c
===================================================================

Documentation/accounting/getdelays.c +1 -1

@@ -196,7 +196,7 @@ void print_delayacct(struct taskstats *t
 	       "IO    %15s%15s\n"
 	       "      %15llu%15llu\n"
 	       "MEM   %15s%15s\n"
-	       "      %15llu%15llu\n"
+	       "      %15llu%15llu\n",

This change looks good!

Quoted 8 lines

Documentation/accounting/getdelays.c +0 -0

 	       "count", "real total", "virtual total", "delay total",
 	       t->cpu_count, t->cpu_run_real_total, t->cpu_run_virtual_total,
 	       t->cpu_delay_total,

@@ -335,17 +335,17 @@ int main(int argc, char *argv[])
 		}
 	}
 

Quoted 4 lines

Documentation/accounting/getdelays.c +0 -4

-	if (tid) {
-		rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
-			      cmd_type, &tid, sizeof(__u32));
-		PRINTF("Sent pid/tgid, retval %d\n", rc);

Documentation/accounting/getdelays.c int main(int argc, char *argv[])

Quoted 10 lines

Documentation/accounting/getdelays.c +7 -3

-		if (rc < 0) {
-			fprintf(stderr, "error sending tid/tgid cmd\n");
-			goto done;
+	do {
+		if (tid) {
+			rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
+				      cmd_type, &tid, sizeof(__u32));
+			PRINTF("Sent pid/tgid, retval %d\n", rc);
+			if (rc < 0) {
+				fprintf(stderr, "error sending tid/tgid cmd\n")

Quoted 8 lines

Documentation/accounting/getdelays.c +2 -2

+				goto done;
+			}
 		}
-	}
 
-	do {
 		int i;
 

Documentation/accounting/getdelays.c int main(int argc, char *argv[]) · line 433

Quoted 6 lines

Documentation/accounting/getdelays.c +1 -0

 		rep_len = recv(nl_sd, &msg, sizeof(msg), 0);

@@ -430,6 +430,7 @@ int main(int argc, char *argv[])
 			}
 			na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
 		}
+		sleep(2);

Is this really required? a sleep() in the code. Why do we do multiple send_cmd()'s in the do loop? I'll test and get back.

Quoted 2 lines

Is this really required? a sleep() in the code. Why do we do multiple send_cmd()'s in the do loop? I'll test and get back.

I needed to send another command to receive more data. Without the per loop send_cmd, I never got any more stats.

Should we receive more data without the additional send_cmd? I've been running with:
./getdelays -d -p 1 -l

Mikey

Interesting, we never used -l that way. We used -l to get data for all exiting tasks

./getdelays -d -l

For the usage you've mentioned, I'd use

while :
do

	sleep 2
	./getdelays -p 1 -d

done

I guess your changes change getdelays and since there are other ways to obtaining the same data, I'd remove the last bit of changes made to send the TGID often to get data.

b663a79c191508f27cd885224b592a878c0ba0f6 incorrectly removed a comma from a printf statement. This causes corruption in the output printing or a seg fault.

Signed-off-by Michael Neuling <[email protected]>

---
 Documentation/accounting/getdelays.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

akpm: please replace documentation-fix-getdelaysc-example-l-option-and-segv.patch with this.

Index: linux-2.6-ozlabs/Documentation/accounting/getdelays.c
===================================================================