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System freezes when using VTune with __itt_resume() and __itt_pause()

scretchi
Beginner
85 Views
Hello,

my system freezes when i try to collect
CPU_CLK_UNHALTED.CORE
CPU_CLK_UNHALTED.REF
INST_RETIRED.ANY

with the new __itt_resume() and __itt_pause() calls under Linux. Only Reset-Button bring the system to life again.
Under vtune 9.1 the collection worked fine with VTResume() and VTPause().

my code looks like this:

static void functionxyz (Macroblock *currMB)
{
__itt_resume();

all I want to collect

__itt_pause();
}
the function is called several 1000 times in a run

Hotspot collection is producing no crash and is switching in the gui from pause to collecting and back for some time but the result is 0 s. EBS freezes the system, but only in this case. I inserted the resume and pause calls on another part of the code, so that there was a lot of work between the calls (including that I want to collect) and then EBS works fine. I tried several Sample after values between 5000 (I used in 9.1) and 1200000 but nothing changed.

Additional problem is that I used a trial version of 9.1 and it expired last week. So I had to use the new vtune because I can't find a link to the old one.

My CPU: Intel Core2 CPU 6600 @ 2.40GHz

Any ideas what the problem is?

Thanks
Scretchi
0 Kudos
5 Replies
Vladimir_T_Intel
Moderator
85 Views

HiScretchi,

Doesnt you system freeze without the itt API? Looks like you set too small SAV. Try to default it to 2,000,000.

scretchi
Beginner
85 Views
Hi Vladimir,

Collection without itt API works fine, even with SAV 1,200,000
I just tried with API and SAV 2,000,000 and it freezes again.
Vladimir_T_Intel
Moderator
85 Views
Probably the amount of work is too small, and the sampling driver is switching on and off all the time.
Please, let us know the VTune Amplifier XE build number (Menu->Help->About->Details) you were using.
scretchi
Beginner
85 Views
I am using build 119041
Vladimir_T_Intel
Moderator
85 Views
OK. I'll check if there any constrains on frequent collection switching.
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