Displaying 20 results from an estimated 1000 matches similar to: "speculative tracing on nevada builds ?"
2009 Jul 24
9
getting extra characters with printf(copyin(a, b))
Hi,
I have a situation where a DTrace script is printing out extra characters, despite the copyin() call giving a specific length. Can anyone think of why this might be? It''s fine the first time all of the probes fire, but on a second run of my generating operations, I get junk in there. For example:
set setop length 5, FOUND KEY, STORED
set setop length 5, FOUND KEY, STORED
get
2006 May 24
2
Reading external files with dtrace
I''d like to be able to dynamically read external configuration files within a dtrace script. I know dtrace allows inclusion of C header files but only at the preprocessing stage.
What we need to do is dynamically enable/disable probes based on current application settings. I''d rather not have a bunch of independant scripts running and being started and killed whenever the
2005 Aug 12
3
Funny output from write syscall
I have a clause that look like this:
syscall::write:entry
/execname == "ntpd" && self->recspec/
{
speculate(self->recspec);
printf(" fd=%d buf=%d\n%s",arg0,arg2,
stringof(copyin(arg1,arg2-1)));
}
The ntpd program always write a \n trminated string in this
context, so I used the "arg2-1" to drop the \n.
This works
2007 Jul 30
3
dtrace
hi fnds,
i want to print the filenames on which the stat system
call is acting when a stat system call is invoked. can anyone can help
me this regard.
Thanks
jeevan
2005 Sep 15
10
Can I use printa() for printing multiple agg regations?
Hi Bryan,
> Does that sit well with everyone?
Seems fine to me.
Just revisiting one of Dragan''s points, though (sorry if I missed the
answer) - is there a reason for making this global (via a #pragma) rather
than, say, simply providing two functions which print in the different
orders? e.g. printa() for sort by sample, printak() for sort by key.
My reason for wanting to do both in
2005 Oct 31
11
Aggregation elements
Howdy,
Is there a method to get the number of elements in an aggregation? Are the
results stored in an aggregation guaranteed to be in any type of order?
Thanks for any insight,
- Ryan
--
UNIX Administrator
http://daemons.net/~matty
2006 Sep 21
1
Dtrace script compilation error.
Hi All,
One of the customer is seeing the following error messages.
He is using a S10U1 system with all latest patches.
Dtrace script is attached.
I am not seeing these error messages on S10U2 system.
What could be the problem?
Thanks,
Gangadhar.
------------------------------------------------------------------------
rroberto at njengsunu60-2:~$ dtrace -AFs /lib/svc/share/kcfd.d
dtrace:
2008 Apr 20
1
dtrace script to monitor file access
A user has asked us to find out who is changing one of their files and how it is being changed. I came up
with the script below:
#!/usr/sbin/dtrace -s
#pragma D option quiet
BEGIN
{
printf("\n Timestamp gid uid pid ppid execname function current directory file name\n\n");
}
syscall::open:entry,
2006 Mar 24
3
Triggering on close of a written file.
I have just started my first ''serious'' dtrace script and can use some
advice.
I want to have a probe triggered when close() occurs after a
succesfull write of /etc/hosts ( I want to regenerate the nameserver
zone files
from /etc/hosts after it has changed)
At the moment I have the following code:
syscall::open*:entry,
syscall::creat*:entry
{
self->file=arg0;
2006 Sep 20
3
committing multiple speculations in a single probe
While using DTrace to track down a problem recently, we came across an
unexpected restriction: the compiler will not permit different
speculations to be committed in the same instance of a probe identifier.
For instance, consider the following useless D script:
#!/usr/sbin/dtrace -s
#pragma D option nspec=2
BEGIN {
spec1 = speculation();
spec2 = speculation();
}
END {
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 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
2005 Jul 19
2
variable size limit & documentation
Bryan,
I''m trying to use a Dtrace script with a modest size
global variable and hit a problem.
Looking for a solution, I turn to the docs and notice
that option "dynvarsize" appears just once in the docs,
and it refers you to Chapter 3, where there is no mention.
It doesn''t help me anyhow.
I have:
#!/usr/sbin/dtrace -qws
#pragma D option dynvarsize=2000000
2006 Sep 06
3
Dtrace Snooping
Dear dtrace Experts,
I have seen some dtrace utilities like opensnoop and execsnoop etc.
My interest is to write a simple script that can snoop the files which
uses the 3 syscalls like open,create,unlink.
I have gone through dtrace oneliners that can do the same :
dtrace -n ''syscall::open*:entry { printf("%s %s",execname,copyinstr(arg0));}''
dtrace -n
2006 Aug 08
9
Handling userland char ** pointers
I''ve been trying to get access to a userland string that''s behind a
second level pointer using DTrace, but I can''t seem to get it to work.
I started with the example on the Team DTrace Tips and Tricks slides:
trace(copyinstr(*(uintptr_t *)copyin(arg0, curpsinfo->pr_dmodel ==
PR_MODEL_ILP32 ? 4 : 8)));
And when I couldn''t get it to work, I started
2005 Sep 27
2
Invalid address error message
Hi,
I ran a d-program with syscall::open:entry probe but got the following
error messages sometimes:
dtrace: error on enabled probe ID 1 (ID 14: syscall::open:entry): invalid
address (0xff34e000) in predicate at DIF offset 76
dtrace: error on enabled probe ID 6 (ID 14: syscall::open:entry): invalid
address (0xff34e000) in predicate at DIF offset 28
I don''t know how to interpret these
2007 Aug 14
8
sh DTrace provider available
As noted on my blog and at
http://www.opensolaris.org/os/community/dtrace/shells/ I''ve made
available a DTrace provider for the Bourne shell. Before anyone starts
yelling at me for not starting with another shell, read the blog I made
explaining why we started with shell (link on the community page
referenced above).
For /bin/sh, I''ve put up something akin to a chapter in
2005 Sep 08
3
DTrace typewriter
G''Day Folks,
I''ve found another use of dtrace, this makes your console keyboard
sound like a typewriter.
http://www.brendangregg.com/DTrace/typewriter-0.70.tar.gz
I''ve only tested it on an UltraSPARC 5 and a Pentium laptop so far, more
to follow.
Ok, sorry, not actually a practical use of DTrace. :)
Enjoy!
Brendan
[Sydney, Australia]
2007 Nov 27
4
DTrace unconference?
All,
With Jon Haslam''s exciting news about the DTrace doc wiki (if you haven''t
seen it yet, make your way to http://wikis.sun.com/display/DTrace), and with
some of the discussion with the Apple folks, I''m wondering if the time
isn''t right for something of a DTrace summit, perhaps as an unconference.
The idea here would not be a DTrace user group (though that
2005 Dec 22
9
truncating aggregation output only
Hello dtrace-discuss,
Sometimes I want to run a script for some time and every n second
output N top entries. trunc() isn''t suitable here as it also removed
keys/values. I want it ''coz over time if I use sum() entries which
are normally truncated can actually get to top over a time.
Maybe printa() extension, something like: printa(@b[10]) - to output
top 10?
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