CG: note that CPU threads affect cell count in regtests (issue 3257)

[lilypond.git] / Documentation / contributor / regressions.itexi

diff --git a/Documentation/contributor/regressions.itexi b/Documentation/contributor/regressions.itexi
index 7bca714f2c412b1aa56a77962c98e5fa7731216b..8b600465f5ffbfda13c6b774b862846fab55d258 100644 (file)
--- a/Documentation/contributor/regressions.itexi
+++ b/Documentation/contributor/regressions.itexi
@@ -135,6 +135,11 @@ something is suspicious!
 @item
 Profile files: give information about
 TODO?  I don't know what they're for.
+Apparently they give some information about CPU usage.  If you got
+tons of changes in cell counts, this probably means that you compiled
+@code{make test-baseline} with a different amount of CPU threads than
+@code{make check}. Try redoing tests from scratch with the same
+number of threads each time -- see @ref{Saving time with the -j option}.
 
 @end itemize
 
@@ -209,7 +214,7 @@ Run @code{make} with current git master without any of your changes.
 
 @item
 Before making changes to the code, establish a baseline for the comparison by
-going to the @file{lilypond-git/build/} directory and running:
+going to the @file{$LILYPOND_GIT/build/} directory and running:
 
 @example
 make test-baseline