hp2ps silently discards samples
Consider the following hp file:
JOB "whatever"
DATE "Sat Feb 21 12:56 2015"
SAMPLE_UNIT "seconds"
VALUE_UNIT "bytes"
BEGIN_SAMPLE 0.00
MAIN 1000
END_SAMPLE 0.00
BEGIN_SAMPLE 0.00
MAIN 100
END_SAMPLE 0.00
BEGIN_SAMPLE 0.01
MAIN 500
END_SAMPLE 0.01
hp2ps will generate a graph showing heap usage going from 100 bytes to 500 bytes... not 1000-100-500 as expected. This is because hp2ps only uses the last sample with the same timestamp.
These hp files show in practice because GHC doesn't output BEGIN_SAMPLE entries with enough precision, see also https://phabricator.haskell.org/D679 to increase the precision.
Trac metadata
Trac field | Value |
---|---|
Version | 7.11 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Profiling |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |