Details

Autor(en) / Beteiligte

• Hoefler, T.
• Schneider, T.
• Lumsdaine, A.

Titel

Accurately measuring collective operations at massive scale

Ist Teil von

• 2008 IEEE International Symposium on Parallel and Distributed Processing, 2008, p.1-8

Ort / Verlag

IEEE

Erscheinungsjahr

2008

Quelle

IEEE Xplore

Beschreibungen/Notizen

• Accurate, reproducible and comparable measurement of collective operations is a complicated task. Although different measurement schemes are implemented in well- known benchmarks, many of these schemes introduce different systematic errors in their measurements. We characterize these errors and select a window-based approach as the most accurate method. However, this approach complicates measurements significantly and introduces a clock synchronization as a new source of systematic errors. We analyze approaches to avoid or correct those errors and develop a scalable synchronization scheme to conduct benchmarks on massively parallel systems. Our results are compared to the window-based scheme implemented in the SKaMPI benchmarks and show a reduction of the synchronization overhead by a factor of 16 on 128 processes.