32-bit Linux perf failures

[Herbert Valerio Riedel]

On 2014-02-20 at 16:26:33 +0100, Mateusz Kowalczyk wrote:

[...]

> While I technically have the push permissions, I'm not a GHC dev. I feel
> like it'd be inappropriate to push in such a ‘fix’ myself. I can post a
> full validate log if that contains information one would need to update
> the numbers.

fyi, the relevant information from the validate log are the parts that
looks like:

,----
| =====> T4801(normal) 1527 of 3902 [0, 0, 0] 
| cd ./perf/compiler && '/workspace/GHC/ghc/bindisttest/install   dir/bin/ghc' -fforce-recomp -dno-debug-output -no-user-package-db -rtsopts -fno-ghci-history -c T4801.hs   +RTS -V0 -tT4801.comp.stats --machine-readable -RTS -static >T4801.comp.stderr 2>&1
| max_bytes_used value is too high:
|     Expected    max_bytes_used: 22646000 +/-10%
|     Lower bound max_bytes_used: 20381400 
|     Upper bound max_bytes_used: 24910601 
|     Actual      max_bytes_used: 25113136 
| *** unexpected failure for T4801(normal)
`----

> Even if I wanted to, I have no idea how to go about updating the
> numbers! Is there a guide of some sort available? I was unable to find
> anything.

Here's some related information you may have already found yourself
(although it does not explain how to actually update the numbers):

  https://ghc.haskell.org/trac/ghc/wiki/Building/RunningTests/Adding#Performancetests

The basic idea for updating the numbers though is to find an
explaination for the change, and then update the expected range while
leaving a comment with the previous value, and when it changed, as well
as a note about the reason for the change. You should easily find many
examples of that in the testsuite.

HTH,
 hvr