Difference between revisions of "VPP/cpel"

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(Created page with "=== CPEL Performance Event Log Files === This page describes the CPEL file format. Over the last decade, we've constructed a set of tools to collect, display and report fine...")
 
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=== File Format ===
 
=== File Format ===
 +
This table describes the CPEL file format.
 +
 +
{|
 +
|Octet offset
 +
|Data
 +
|-
 +
|0x0
 +
|Endian bit (0x80), File Version, 7 bits (0x1...0x7F)
 +
|-
 +
|0x1
 +
|Unused, 8 bits
 +
|-
 +
|0x2-0x3
 +
|Number of sections (16 bits) (NSECTIONS)
 +
|-
 +
|0x4
 +
|File date (32-bits) (POSIX "epoch" format)
 +
|-
 +
|0x8
 +
|Type of first section (32 bits)
 +
|-
 +
|0xC
 +
|Length of first section (32 bits), not including type and length
 +
|First section data
 +
|-
 +
|NSECTIONS-1, or up to 64K-2 additional sections
 +
|...
 +
|-
 +
|...
 +
|Type of next section (32 bits)
 +
|-
 +
|...
 +
|Length of next section (32 bits)
 +
|-
 +
|Next section data
 +
|...
 +
|}

Revision as of 15:34, 12 February 2016

CPEL Performance Event Log Files

This page describes the CPEL file format. Over the last decade, we've constructed a set of tools to collect, display and report fine-grained performance event data. As the toolset has grown, limitations inherent in previous file formats have become an issue.

CPEL files consist of a set of sections, similar to ELF-files. Specific tools may or may not understand a particular section. Sections are TLV's: (tag, length, value) tuples. Specific tools can skip or copy sections without needing to know anything about the data therein.

File Format

This table describes the CPEL file format.

Octet offset Data
0x0 Endian bit (0x80), File Version, 7 bits (0x1...0x7F)
0x1 Unused, 8 bits
0x2-0x3 Number of sections (16 bits) (NSECTIONS)
0x4 File date (32-bits) (POSIX "epoch" format)
0x8 Type of first section (32 bits)
0xC Length of first section (32 bits), not including type and length First section data
NSECTIONS-1, or up to 64K-2 additional sections ...
... Type of next section (32 bits)
... Length of next section (32 bits)
Next section data ...