User Guide

Contents

assume-single-data-transfer

Assume data is transferred only once for each offload, and all instances share that data.

Syntax

--assume-single-data-transfer
--no-assume-single-data-transfer
Default
Off (no-assume-single-data-transfer)
Actions Modified
collect
=projection
Usage
When the option is disabled, use an
optimistic
approach to estimate data transfer taxes: assume data is only transferred
once
for each offload, and all instances share that data.
When the option is enabled, use a
pessimistic
approach to estimate data transfer taxes: assume
each
data object is transferred for every instance of an offload that uses it. This method assumes no data re-use between calls to the same kernel.
Data Parallel C++ (DPC++), OpenMP* target, and OpenCL™ kernels running on a CPU are still counted only once because the call count for these kernels is usually inflated.
Make sure to enable the data transfer analysis during the Trip Counts collection with
--data-transfer=[light | medium |full]
or
--enable-data-transfer-analysis
.
Example
  1. Run Survey Analysis.
  2. Run Trip Counts and FLOP analyses of the Characterization stage with the light data transfer.
  3. Model your application performance assuming data is transferred only once.
$ advisor --collect=survey --stackwalk-mode=online --static-instruction-mix --project-dir=./advi -- myApplication
$ advisor --collect=tripcounts --flop --data-transfer=light --project-dir=./advi -- myApplication
$ advisor --collect=projection --assume-single-data-transfer --project-dir=./advi

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.