user space probe in ubuntu 14.04

user space probe in ubuntu 14.04

[Gareth]

Hey guys

What's the requirements for using systemtap in ubuntu 14.04 (kernel
version = 3.13)?

I have installed kernel-image package and found many probes by 'stap
-l 'kernel.function("acpi_*")'. However I sill can't use
process("xxx").xxx

I tried find online documents and I'm sure uprobe is enabled, utrace
is not. But that document said utrace is deprecated long time ago...

My output is here: http://paste.openstack.org/show/461444/


-- 
Gareth

Cloud Computing, OpenStack, Distributed Storage, Fitness, Basketball
OpenStack contributor, kun_huang@freenode
My promise: if you find any spelling or grammar mistakes in my email
from Mar 1 2013, notify me
and I'll donate $1 or ￥1 to an open organization you specify.

Re: user space probe in ubuntu 14.04

[David Smith]

On 09/14/2015 09:54 AM, Gareth wrote:
> Hey guys
> 
> What's the requirements for using systemtap in ubuntu 14.04 (kernel
> version = 3.13)?
> 
> I have installed kernel-image package and found many probes by 'stap
> -l 'kernel.function("acpi_*")'. However I sill can't use
> process("xxx").xxx
> 
> I tried find online documents and I'm sure uprobe is enabled, utrace
> is not. But that document said utrace is deprecated long time ago...
> 
> My output is here: http://paste.openstack.org/show/461444/

From your output, I see you are trying to use markers, since you did the
following:

   probe process("/usr/sbin/mysqld").mark("query__start")

So, the first thing to do is make sure that your /usr/sbin/mysqld was
compiled with markers. Try the following:

# readelf -n /usr/bin/mysql | fgrep Name

If that works, try:

# stap -l 'process("/usr/sbin/mysqld").mark("*")'


-- 
David Smith
dsmith@redhat.com
Red Hat
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)

Re: user space probe in ubuntu 14.04

[Gareth]

Thanks for your hint David

I have just installed mysql related dbgsym packages, but it still doesn't work:

http://paste.openstack.org/show/462299/

Btw the '^' at line 25 and line 30 is pointing at the 'p' of 'process'.

No more ideas now : (

On Tue, Sep 15, 2015 at 12:29 AM, David Smith <dsmith@redhat.com> wrote:
> On 09/14/2015 09:54 AM, Gareth wrote:
>> Hey guys
>>
>> What's the requirements for using systemtap in ubuntu 14.04 (kernel
>> version = 3.13)?
>>
>> I have installed kernel-image package and found many probes by 'stap
>> -l 'kernel.function("acpi_*")'. However I sill can't use
>> process("xxx").xxx
>>
>> I tried find online documents and I'm sure uprobe is enabled, utrace
>> is not. But that document said utrace is deprecated long time ago...
>>
>> My output is here: http://paste.openstack.org/show/461444/
>
> From your output, I see you are trying to use markers, since you did the
> following:
>
>    probe process("/usr/sbin/mysqld").mark("query__start")
>
> So, the first thing to do is make sure that your /usr/sbin/mysqld was
> compiled with markers. Try the following:
>
> # readelf -n /usr/bin/mysql | fgrep Name
>
> If that works, try:
>
> # stap -l 'process("/usr/sbin/mysqld").mark("*")'
>
>
> --
> David Smith
> dsmith@redhat.com
> Red Hat
> http://www.redhat.com
> 256.217.0141 (direct)
> 256.837.0057 (fax)



-- 
Gareth

Cloud Computing, OpenStack, Distributed Storage, Fitness, Basketball
OpenStack contributor, kun_huang@freenode
My promise: if you find any spelling or grammar mistakes in my email
from Mar 1 2013, notify me
and I'll donate $1 or ￥1 to an open organization you specify.

Re: user space probe in ubuntu 14.04

[Gareth]

btw, below are the packages I have installed

http://paste.openstack.org/show/462471/

On Tue, Sep 15, 2015 at 11:46 AM, Gareth <academicgareth@gmail.com> wrote:
> Thanks for your hint David
>
> I have just installed mysql related dbgsym packages, but it still doesn't work:
>
> http://paste.openstack.org/show/462299/
>
> Btw the '^' at line 25 and line 30 is pointing at the 'p' of 'process'.
>
> No more ideas now : (
>
> On Tue, Sep 15, 2015 at 12:29 AM, David Smith <dsmith@redhat.com> wrote:
>> On 09/14/2015 09:54 AM, Gareth wrote:
>>> Hey guys
>>>
>>> What's the requirements for using systemtap in ubuntu 14.04 (kernel
>>> version = 3.13)?
>>>
>>> I have installed kernel-image package and found many probes by 'stap
>>> -l 'kernel.function("acpi_*")'. However I sill can't use
>>> process("xxx").xxx
>>>
>>> I tried find online documents and I'm sure uprobe is enabled, utrace
>>> is not. But that document said utrace is deprecated long time ago...
>>>
>>> My output is here: http://paste.openstack.org/show/461444/
>>
>> From your output, I see you are trying to use markers, since you did the
>> following:
>>
>>    probe process("/usr/sbin/mysqld").mark("query__start")
>>
>> So, the first thing to do is make sure that your /usr/sbin/mysqld was
>> compiled with markers. Try the following:
>>
>> # readelf -n /usr/bin/mysql | fgrep Name
>>
>> If that works, try:
>>
>> # stap -l 'process("/usr/sbin/mysqld").mark("*")'
>>
>>
>> --
>> David Smith
>> dsmith@redhat.com
>> Red Hat
>> http://www.redhat.com
>> 256.217.0141 (direct)
>> 256.837.0057 (fax)
>
>
>
> --
> Gareth
>
> Cloud Computing, OpenStack, Distributed Storage, Fitness, Basketball
> OpenStack contributor, kun_huang@freenode
> My promise: if you find any spelling or grammar mistakes in my email
> from Mar 1 2013, notify me
> and I'll donate $1 or ￥1 to an open organization you specify.



-- 
Gareth

Cloud Computing, OpenStack, Distributed Storage, Fitness, Basketball
OpenStack contributor, kun_huang@freenode
My promise: if you find any spelling or grammar mistakes in my email
from Mar 1 2013, notify me
and I'll donate $1 or ￥1 to an open organization you specify.

Re: user space probe in ubuntu 14.04

[Frank Ch. Eigler]

academicgareth wrote:

> http://paste.openstack.org/show/462471/
> [...]
>>>    probe process("/usr/sbin/mysqld").mark("query__start")

These ubuntu 14 builds of mysql did not include the sys/sdt.h markers
necessary for use of the .mark() probes.  "readelf -n /usr/sbin/mysqld"
fails to show any NT_STAPSDT notes.

If you installed mysql-{client,server}-5.5-dbgsym, you should be
able to use .function() etc. probes ... but something's broken in the
ubuntu build system:

% dpkg -l 'mysql-server-5.5*'
ii  mysql-server-5.5                           5.5.44-0ubuntu0.14.04.1    amd64                      MySQL database server binaries and system database setup
ii  mysql-server-5.5-dbgsym                    5.5.44-0ubuntu0.14.04.1    amd64                      debug symbols for package mysql-server-5.5

% stap -L 'process("/usr/sbin/mysqld").function("*")'
[empty!]

% readelf -n /usr/sbin/mysqld
[...]
    Build ID: 7c5b991d6ba0d7722a41f9a39e2915f6a354a1c7

% dpkg -L mysql-server-5.5-dbgsym | grep 5b99
[empty!]

So the dbgsym package doesn't contain debuginfo for that actual build,
despite the identical version numbers.  Please raise this problem with
ubuntu.


The mysql-client-5.5{-dbgsym} peers appears less broken:

% stap -L 'process("/usr/bin/mysqldump").function("*")'
[... lots of delicious stuff ...]


- FChE