Displaying 20 results from an estimated 300 matches similar to: "suspicious dtrace results"
2007 Jul 11
5
Error trying to count return points in functions.
Whilst trying out some D to get an insight into what is the most
common reason for a given function to return, I have bumped
into an error I don''t understand.
The first take on what I was trying to do was:
# dtrace -n ''fbt:ip:ip_input:return{@home[arg0] = count();}''
and all was well. The next step was:
# dtrace -n
2012 Sep 18
1
Cochran-Mantel-Haenszel test
Hello,
I have some satellite tag time-at-depth (TAD) frequency data that I
would like some help with.
The data was transmitted via satellite as percent time spent in each of
7 depth bins (0m, 0-1m, 1-10m, 10-50m etc.), binned over 6-hour
intervals. I categorized each row of data corresponding to a date and
time into summer vs. winter, and day vs. night, and then summed and
averaged the given
2008 Sep 09
1
DTrace and shared memory id
Hello all,
I saw this question about a year back in the archive[1], but with no
final answer.
I would like to trace shmget calls and also get the id of the shared
memory segment.
That script looked like[2], but we dont get the id since arg1 is the
errno value.
How do i access the shm id, i would need this to debug a customer
problem but i don''t have time to learn it the hard
2011 Jan 05
0
dtrace-discuss Digest, Vol 69, Issue 2
Hello Srikant -
A quantization distributes the results of your aggregation into ranges
ordered by a power-of-two. Presumably what you''d do in your script is
capture the inclusive elapsed time of each function call in your library,
then use this quantization to see how tightly-banded the times are. Perhaps
there''s some blocking I/O in some of your calls, for example, in which
2007 Dec 29
1
why was some stack information lost.
I wrote a simple c programme and do some dtrace test. the progromme shows below(write.c):
///////////////////////////////
#include<stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
char *value="hello,my name is wanjm\n";
void main()
{
int fd;
fd=open("/export/home/wanjm/temp/read.txt",O_RDWR|O_CREAT);
while(1)
{
2007 Aug 23
1
EOF broken on zvol raw devices?
> I tried to copy a 8GB Xen domU disk image from a zvol device
> to an image file on an ufs filesystem, and was surprised that
> reading from the zvol character device doesn''t detect "EOF".
>
> On snv_66 (sparc) and snv_73 (x86) I can reproduce it, like this:
>
> # zfs create -V 1440k tank/floppy-img
>
> # dd if=/dev/zvol/dsk/tank/floppy-img
2011 Jan 05
0
Understand the dtrace quantize output
Hi,
I am kind of new to DTrace , I have written a script to time function calls
in our application library ,
Wanted to know how to interpret the output from quantize of the elapsed time
in each function call , here is a sample
Here is the entry and return function for the library that is being traced
pid$1:libswduar::entry
{
duarEntry[probefunc] = timestamp;
2006 Sep 12
3
dtrace reports different counts depending on what is being traced
We are using following dtrace script to analyze an application. However
we see different number of lwp_yield and yield calls reported depending
on whether we trace mutex_lock or mutex_unlock or not. The number
reported when we are not tracing mutex_lock or mutex_unlock is higher.
What could be going on here and which one is the correct number. This is
on S10 U2.
Thanks,
Rao.
2006 Feb 17
3
CPU time stats
hi,
I am trying to find out the avg cpu time spent in each of my user
methods (exclusive of other methods invoked by a method).
Hence the following snippet failed miserably:
-----------------------
pid$target:a.out::entry
{ time[probefunc] = timestamp;}
pid$target:a.out::return
{ @spent[probefunc] = avg(timestamp - time[probefunc]);}
END
{ printa(@spent);}
2009 Mar 28
4
mac_srs_rx_poll_ring thread never stop polling hardware in kernel
Recently I found that the mac_srs_rx_poll_ring thread may never stop in
kernel, please see the following mpstat, cpu 2 is in 100% kernel usage, but
no syscalls and no interrupts.
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt
idl
0 0 0 0 300 100 0 0 1 0 0 0
0 0 0 100
1 14 0 0 134 68 134 1
2006 Sep 21
2
Probe description does not match any probes
[Perhaps someone could rename this list to dtrace-matt-problems-discuss?]
If I run this script against my binary (which contains a USDT probe called ''concurrentq-latency''):
:::
/ probename == "concurrentq-latency" /
{
printf("[%s]:[%s]:[%s]\n", probeprov, probefunc, probename);
}
I get this output:
dtrace: script ''testq.d'' matched 46056
2006 Mar 01
3
vtimestamp skew, after restorectx()
Hello,
I''m using the below dtrace script to capture the flow and times of
kernel functions, from an ioctl() call. After an entry into
restorectx(), the trace of startimestamp - vtimestamp makes a dramatic
jump downwards. Here''s the snippet showing the jump...
6 -> di_checkmem 8 220176600
6 <- di_checkmem
2008 May 20
6
Dtrace queries - predicates & func arg tracing
[1] Predicates in one-liners
I would like to list the probe modules in my executable and then
dynamically create a dscript to trace execution of those modules alone
(by excluding the 3rd party and system libraries). I tried the below
script without success. The conditional given in the predicate is not
taking effect. Why is this so ?
$ dtrace -ln ''pid$target:::
2007 Jun 29
1
dtrace and Xorg don''t always mix
I''m wondering if I should file a bug against this or is this just a case of a user doing something stupid :)
I ran the following script on my desktop:
#!/usr/sbin/dtrace -s
pid9276:::entry
{
@counting[probefunc] = count();
}
And my Xsession immediately crashed and through me back to the login screen. My OS is
5.11 snv_50 i86pc i386 i86pc with a dual core amd chip and 2G or
2006 Jul 10
5
Definition of "anchored" and "unanchored" probes
Referring to the DTrace manual:
"Module If this probe corresponds to a specific program location,
the name of the module in which the probe is located. This name is
either the name of a kernel module or the name of a user library.
Function If this probe corresponds to a specific program location,
the name of the program function in which the probe is located."
and then ...
2006 Jul 30
6
zfs mount stuck in zil_replay
Hello ZFS,
System was rebooted and after reboot server again
System is snv_39, SPARC, T2000
bash-3.00# ptree
7 /lib/svc/bin/svc.startd -s
163 /sbin/sh /lib/svc/method/fs-local
254 /usr/sbin/zfs mount -a
[...]
bash-3.00# zfs list|wc -l
46
Using df I can see most file systems are already mounted.
> ::ps!grep zfs
R 254 163 7 7 0 0x4a004000
2007 Feb 15
2
profile provider: is it me doing stupid things?
Just showing someone how great DTrace is and then we spot something I do not understand.
Of course it can be a major misunderstanding of myself. Would appreciate another (expert) look upon this.
The goal we try to achieve is trying to get insight if there is a bursty nature in the time slot when system calls are done. Following DTrace snippet is tried:
dtrace -q -p 3173 -n
2007 Feb 13
2
zpool export consumes whole CPU and takes more than 30 minutes to complete
Hi.
T2000 1.2GHz 8-core, 32GB RAM, S10U3, zil_disable=1.
Command ''zpool export f3-2'' is hung for 30 minutes now and still is going.
Nothing else is running on the server. I can see one CPU being 100% in SYS like:
bash-3.00# mpstat 1
[...]
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 0 0 67 220 110 20 0 0 0 0
2008 Oct 01
0
''introspect'' method
(PS: another idea that comes along the same lines as a dumper function and IMO would be helpful is an ''introspect'' function. Given an argument:
introspect(probefunc)
it returns back the expected arguments for the probe func, their datastructures, as well as the syntax on how to dereference them. If an intelligent copyinstr comes out, this would be easy to write, and would
2007 Mar 13
0
about use dtrace analyze tomcat''s situation
everyone Here:
How do you do!
dtrace is interesting. I am studing how to write dtrace script and analyze situation.
I read dtrace_example.pdf and 819-6959.pdf document more than five times with careful.
because I am newbie to studing dtrace.so I still don''t know how to begin.
for question:
1. What consumes time?
2. Which system call(s) consume(s) time?