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Re: Script to look for system call errors


Hi all,

On Thu, Apr 2, 2009 at 5:50 PM, Mark Wielaard <mjw@redhat.com> wrote:
> On Wed, 2009-04-01 at 22:18 +0800, Eugene Teo wrote:
>> Last night I was working on a script to look for system call errors.
>> This is particularly useful for identifying misbehaving userspace
>> applications. The script prints out useful information about the top 20
>> errors every 5 secs.
>>
>> With the script, I found out that mixer_applet2 wakes up very
>> frequently[1], gnome-panel tries to add a collection of watches every
>> second for files that do not exist, hald tries to open some
>> battery-related sysfs files over and over again even though I am running
>> the script in a virtual machine. mjw has a couple of interesting
>> observations with the script as well.
>
> Yeah, good script! It would be nice if you could set the timeout and
> number of output lines. Some observations that immediately sprung up
> from using it:

Thanks for the feedback!

The return probes are shortened. You can now set the timeout and
number of output lines. By default, timeout is 5 secs, and the number
of output lines is 20.

The script depends on a couple of functions that were committed
recently - http://is.gd/qylL and http://is.gd/qylX

You can run the script in the following ways:
$ ./errsnoop.stp
or
$ ./errsnoop.stp 1 25
or
$ ./errsnoop.stp -DMAXMAPENTRIES=20480 1 25

Thanks, Eugene

Attachment: errsnoop.txt
Description: Text document

Attachment: errsnoop.stp
Description: Binary data


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