Failed to create sampling data base on Ubunto 8.04

[ncardoso]

Hi,
I'm using vtune profiler on ubunto 8.04 distro and
when I add "2nd Level Cache Load Misses Retired" and run sampling activity I cannot see the collected results:
"Failed to create sampling data base. Probably .tb5 files are corrupted or doesn't exist."

What is the problem? I installed vtune as sudo user... is that a problem?

What is the event that I use to capture page faults events?

What is the difference between "2nd Level Cache Load Misses Retired", "2nd Level Cache Read Misses" and "2nd Level Cache Read References"? What of this represents the real 2nd cache misses event (Load or Read)?

Thanks,
Nuno Cardoso.

[TimP]

You require sudo privilege to install VTune, but the normal way of running is to create a group with the privilege required to run VTune and include yourself in that group. Without such privilege, VTune won't be able to collect samples.
Among those events, you could count how many times the CPU looks for data in 2nd level cache, how many of those don't find the data there (many of them referring to the same cache line), and how many distinct cache line miss events are processed.

[ncardoso]

Quoting - tim18

You require sudo privilege to install VTune, but the normal way of running is to create a group with the privilege required to run VTune and include yourself in that group. Without such privilege, VTune won't be able to collect samples.
Among those events, you could count how many times the CPU looks for data in 2nd level cache, how many of those don't find the data there (many of them referring to the same cache line), and how many distinct cache line miss events are processed.

Can I capture Page faults with vtune profiler? If I can, what is the event?

[TimP]

Quoting - ncardoso

Can I capture Page faults with vtune profiler? If I can, what is the event?

There are TLB events for each level of TLB, in case that is what you mean.

[ncardoso]

Quoting - tim18

There are TLB events for each level of TLB, in case that is what you mean.

Why the message "Failed to create sampling data base. Probably .tb5 file are corupted or doesn't exit" appears when I configure vtune sampling activity to capture events like 2nd Level Cache Load Misses Retired? The only one that works is "2nd Level Cache Read misses"...

[TimP]

If your collection is divided into several runs, and only the first run works, it would indicate the first sampling session changes the environment so as to prevent subsequent runs from working. Setting up your sampling session to run from a script, with the environment set up entirely in the script, might help.

[ncardoso]

Quoting - tim18

If your collection is divided into several runs, and only the first run works, it would indicate the first sampling session changes the environment so as to prevent subsequent runs from working. Setting up your sampling session to run from a script, with the environment set up entirely in the script, might help.

1) If you are running vtune on linux platform, what is the linux distro you use? (I'm using ubunto 8.04)

2) How can I create a new user with right privileges to run vtune (vtlec)?
- I created a new ubunto user with adminstration privilege, but when I run vtlec with multiple events, like you said before, the collection is divided in mutiple collections, and the only one that works is the first. The other doesn't create .tb5 files. I used "sudo /opt/intel/vtune/bin/vtlec" to run vtune.

3) How can I run vtlec with mutiple events from script file? Can you show me an exemple?

Tahnks,
Nuno Cardoso.

[TimP]

1. I use most often RH5.[2-4], next most often SLES10/11, OpenSuSE11.
2. You could repeat the VTune installation from script. It asks you if it is OK to create the special group (default group name vtune), and invites you to add users to the group. Those operations, of course, are standard sysadmin tasks; not being a sysadmin, I struggle to remember where the commands sit. If that part of the script fails because of Ubuntu deviating from agreed standard linux, that learning is part of the load you take on by choosing Ubuntu. The name of the special group also sits in the script which starts the VTune daemon, so the use of the install script to create the group is advised.
3. You simply set up your job to run from a script which can run from a fresh login, so, for example, you would source iccvars (if using icc), set your working directory, and any required environment variables, as well as putting the run command in the script. Then you simply configure VTune to run the script, designating the module of interest as before, but you don't have to set environment variables and command line parameters in vtlec.

[ncardoso]

Quoting - tim18

1. I use most often RH5.[2-4], next most often SLES10/11, OpenSuSE11.
2. You could repeat the VTune installation from script. It asks you if it is OK to create the special group (default group name vtune), and invites you to add users to the group. Those operations, of course, are standard sysadmin tasks; not being a sysadmin, I struggle to remember where the commands sit. If that part of the script fails because of Ubuntu deviating from agreed standard linux, that learning is part of the load you take on by choosing Ubuntu. The name of the special group also sits in the script which starts the VTune daemon, so the use of the install script to create the group is advised.
3. You simply set up your job to run from a script which can run from a fresh login, so, for example, you would source iccvars (if using icc), set your working directory, and any required environment variables, as well as putting the run command in the script. Then you simply configure VTune to run the script, designating the module of interest as before, but you don't have to set environment variables and command line parameters in vtlec.

Thanks for your answers. Your answers will help me to take some important decisions in the developing of my Phd project.
In the past, I read that Red Hat Linux distro is the sugested linux distro that Intel use to run vtune.

Are you using a real Reh Hat distro, like Red Hat Enterprise Linux 5 Desktop (that distro needs a licency, so you need to pay one), or Are you using Fedora? [2-4] that you refer above is the linux version?

Like you said, when I intall vtune from install.sh script, the instalation process doens't ask me to add a user to vtune group...

Thanks for your help.
Nuno Cardoso.

Note: If I have some doubts in interpret some vtune profiling results, Is that the right forum to put the questions, or I need a special licency from intel to do that?

[TimP]

If you did successfully create the VTune group, you can add users to that group with standard linux tools. I note there are Google hits on how to do that specifically for Ubuntu, in case Ubuntu rejects standard methods.
The CentOS corresponding to a Red Hat version which supports your platform is a conservative choice.
Both Enterprise (supported by VTune) and Open (not specifically supported) SUSE, along with Fedora, have generally worked well with VTune, with those versions generally requiring you to install and configure kernel source so that VTune installer can build a driver.
Yes, the search facilities on this forum, and asking questions here, are appropriate ways to learn about VTune.