Zoom Out and See Better: Scalable Message Tracing for Post-Silicon SoC Debug

Pal, Debjit; Vasudevan, Shobha

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https://hdl.handle.net/2142/98857 Copy

Description

Title

Zoom Out and See Better: Scalable Message Tracing for Post-Silicon SoC Debug

Author(s)

• Pal, Debjit
• Vasudevan, Shobha

Issue Date

2017-11

Keyword(s)

• Post-silicon debug
• Observability
• Tracing hardware
• OpenSPARC T2

Abstract

We present a method for selecting trace messages for post-silicon validation of System-on-Chip (SoC). Our message selection is guided by specifications of interacting flows in common user applications. In current practice, such messages are selected based on designer expertise. We formulate the problem as an optimization of mutual information gain and trace buffer utilization. Our approach scales to systems far beyond the capacity of current signal selection techniques. We achieve an average trace buffer utilization of 98.96% with an average flow specification coverage of 94.3% and an average bug localization to only 21.11% of the potential root causes in our large-scale debugging effort. We present efficacy of our selected messages in debugging and root cause analysis using five realistic case studies consisting of complex and subtle bugs from the OpenSPARC T2 processor.

Publisher

Coordinated Science Laboratory, University of Illinois at Urbana-Champaign

Series/Report Name or Number

Coordinated Science Laboratory Report no. UILU-ENG-17-2203

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/98857

Sponsor(s)/Grant Number(s)

IBM

Owning Collections