OProfile / Bugs / #263 Using operf with multiple events, samples may be attributed to wrong event

#263 Using operf with multiple events, samples may be attributed to wrong event

Milestone: None

Status: closed

Owner: Maynard Johnson

Labels: None

Priority: 5

Updated: 2014-09-11

Created: 2013-12-19

Creator: Maynard Johnson

Private: No

A serious bug was found that affects operf profiling with
multiple events. Samples for an event may be incorrectly
attributed to another event. For example, profiling on
a Sandybridge laptop with CPU_CLK_UNHALTED and INST_RETIRED
events produces the following summary counts from opreport:

  32412 100.000     20104 100.000 foo

Using operf to produce separate profiles for these two events
results in these sample counts:

CPU_CLK_UNHALTED |
samples| %|

  18962 100.000 foo

INST_RETIRED |
samples| %|

  33464 100.000 foo

The attached patch fixes this bug.

1 Attachments

0001-Fix-sample-attribution-problem-when-using-multiple-e.patch

Discussion

Maynard Johnson - 2014-01-02

This patch was committed upstream on Dec 20, 2013.

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Maynard Johnson - 2014-01-02

status: open --> open-fixed

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Maynard Johnson - 2014-09-11

Status: open-fixed --> closed
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Using operf with multiple events, samples may be attributed to wrong event

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#263 Using operf with multiple events, samples may be attributed to wrong event

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