Re: timevar: further work

[Akim Demaille]

The results with getrusage are indeed much more precise.

This is with times.

$ ./_build/7s/tests/bison --trace=time ~/Downloads/Z280/asm1a.y
asm1a2.y: avertissement: 33 conflits par décalage/réduction [-Wconflicts-sr]

Execution times (seconds)
 reader                : 0,0100 ( 2%) usr 0,0000 ( 0%) sys 0,0000 ( 0%) wall
 LR(0)                 : 0,0100 ( 2%) usr 0,0000 ( 0%) sys 0,0000 ( 0%) wall
 outputting report     : 0,0300 ( 7%) usr 0,0000 ( 0%) sys 0,0000 ( 0%) wall
 parser action tables  : 0,0200 ( 4%) usr 0,0000 ( 0%) sys 0,0000 ( 0%) wall
 outputting parser     : 0,0100 ( 2%) usr 0,0000 ( 0%) sys 0,0000 ( 0%) wall
 running m4            : 0,3700 (82%) usr 0,0000 ( 0%) sys 0,0000 ( 0%) wall
 total time            :   0,45             0,00             0,00


This is with getrusage.

$ ./_build/7s/tests/bison --trace=time ~/Downloads/Z280/asm1a.y
asm1a2.y: avertissement: 33 conflits par décalage/réduction [-Wconflicts-sr]

Execution times (seconds)
 reader                : 0,0163 ( 4%) usr 0,0016 (19%) sys
 outputting report     : 0,0273 ( 6%) usr 0,0013 (16%) sys
 parser action tables  : 0,0184 ( 4%) usr 0,0001 ( 1%) sys
 outputting parser     : 0,0109 ( 2%) usr 0,0010 (12%) sys
 running m4            : 0,3794 (83%) usr 0,0040 (47%) sys
 total time            :   0,46             0,01                                
                                                                                
                      


Weirdly enough though, some phases in Bison now completely
disappear. From the report.  For instance, LR(0) that we see
almost at each run with time never shows with getrusage.


Also, I wrote something completely wrong:

> - getrusage offers two choices:
>  - RUSAGE_SELF: the calling process and its threads.
>  - RUSAGE_CHILDREN: main and subprocesses that have been wait’ed.

No, RUSAGE_CHILDREN is _only_ about the children.  Two calls are needed
to get self + children.