Intel Parallel Advisor Workflow
David Valentine
Computer Science
Slippery Rock University
Parallel Advisor: the goal
• Find the sections of your application that,
when parallelized, will give you the best
performance gains and scalability, while
maintaining correct results
Advisor Workflow (from .NET)
“Open Advisor Work flow”
Can also get here from ToolsIntel Advisor XE 2013-Open
Advisor XE Workflow
Simple, 5-step process
-all analysis done on your
serial code
Different Builds needed at
Different Steps in the Workflow
Workflow Stage
Release Build
Survey Target
(Annotate Sources)
Check Suitability
Debug Build
XXX
Check Correctness
(Add Parallel Framework)
XXX
Release Build
Options
C/C++ > General tab
Debug Info Format > Program Database (/Zi)
Compiler: Optimization
Optimization > Maximize Speed (/O2)
Inline Function Expansion > Only_inline (/Ob1)
Compiler: Code Generation
Runtime Library > MultiThreaded DLL (/MD or /MDd)
Linker Options
Generate Debug Info > Yes (/DEBUG)
Different Builds needed at
Different Steps in the Workflow
Workflow Stage
Release Build
Survey Target
(Annotate Sources)
Check Suitability
Debug Build
XXX
Check Correctness
(Add Parallel Framework)
XXX
Debug Build
Options
C/C++ > General tab
Debug Info Format > Program Database (/Zi) or (/ZI)
Compiler > Optimization
Disabled (/Od)
Code Generation
Runtime Library > Multi-Threaded DLL (/MD) or
Multi-Threaded Debug DLL (/MDd)
Linker > Debugging
Generate Debug Info > YES (/DEBUG)
Work Flow Step 1:
Survey Target
• This “hot spot” tool needs a “Release Mode”
configuration along with Project Properties:
– C/C++
• General tab: Debug info to /Zi or /ZI
• Optimization: Max Speed /O2 & Only_Inline /Ob1
• Code Generation: Runtime Library to Multi-threaded /MD or
/MDd
– Linker- Debugging set to YES (/DEBUG)
• Build Project
• Click “Collect Survey Data”
Look at Survey Report
100% of time spent in the loop in function trap.
Double click to see the code involved.
Summary Report
We can see all the time was
spent in a single, timeconsuming loop. We now
have a target to parallelize.
Step 2:
Annotate Source
• The Workflow Advisor gives us 5 tasks:
1. Specify the Intel Advisor XE Include directory
a.
b.
c.
I prefer to set .NET IDE for this. Tools-Options-Projects &
Solutions-VC++ DirectoriesThen drop the box “Show directories for” to Include Files
Browse to “C:\Program Files\Intel\Advisor XE 2013\include”
2. Include the annotation definitions
a)
b)
Go to top of code (in #include’s) and right click
Select Intel Advisor XE 2013 – Insert Annotation Definitions
Reference and the #include will be inserted for you.
3. Specify the library name and directory
Checking Suitability
4. Insert the actual Annotations: highlight & rt-click
ANNOTATE_SITE_BEGIN(MySite1);
for(int i=1; i<numIntervals; i++) {//get the interior
points
ANNOTATE_TASK_BEGIN(MyTask1);
x = xLo + i*width;
area += f(x);
ANNOTATE_TASK_END(MyTask1);
}
ANNOTATE_SITE_END(MySite1);
Checking Suitability
5. Rebuild project (Release configuration)
•
•
The Survey & Suitability tools take RELEASE build
The Correctness tool (when we get there) takes a DEBUG
build.
Suitability Report
We can almost double
speed on dual core
But the tasks
are VERY small
Check Correctness
• Rebuild Project with Debug configuration
a. Compiler: Debug (/Zi)
b. Compiler: Optimization Disabled (/Od)
c. Compiler: Code Generation Runtime Library (/MD or
/MDd)
d. Linker Debugging: Generate Debug info YES (/DEBUG)
• And KNOCK DOWN THE ITERATIONS!

Correctness takes a LONG LONG time
We find a data race error
Each thread tries to update
“area”; we have a data race.
(There is also a bug in Advisor)
Fix data race with lock
ANNOTATE_SITE_BEGIN(MySite1);
for(int i=1; i<numIntervals; i++) {//get the interior
points
ANNOTATE_TASK_BEGIN(MyTask1);
x = xLo + i*width;
ANNOTATE_LOCK_ACQUIRE(&area)
area += f(x);
//add the interior value
ANNOTATE_LOCK_RELEASE(&area)
ANNOTATE_TASK_END(MyTask1);
}
ANNOTATE_SITE_END(MySite1);
Run Correctness again
Clean bill of health!
Now add Parallel Framework
#pragma omp parallel for default(none) \ //make newbie list ALL
private(x) \
//each thread has own x
shared(numIntervals, xLo, width) \ //all share these
reduction(+:area)
//threads combine areas at end
for(int i=1; i<numIntervals; i++) {//get the interior points
x = xLo + i*width;
//makes each iteration independent of others
area += f(x);
//add the interior value ***
}
• Will also need to add:
– #include <omp.h>
– Properties-Configuration- C/C++ -Language-OpenMP Support > Yes
Watch it run!
100% core
usage!
Now on to the Nifties…
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Please respect the work of colleagues
DO NOT POST SOURCE CODE
Give credit back to the authors
DO NOT POST SOURCE CODE
Feel free to tweak the assignments
DO NOT POST SOURCE CODE