ci: macos: Reduce test concurrency

Test performance regresses noticably when using all cores. This is more
pronounced with meson than with autoconf, presumably because meson will
schedule the "full number" of tests more consistently.  8 seems to work
OK.

Discussion: https://postgr.es/m/20220927040208.l3shfcidovpzqxfh@awork3.anarazel.de
Backpatch: 15-, where CI was introduced

diff --git a/.cirrus.yml b/.cirrus.yml
index fe8da021edab38b18cf435816c7459b54401b39e..638850a0fec9cb218336d2162d5a347f3dd8d769 100644 (file)
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -226,7 +226,10 @@ task:
   env:
     CPUS: 12 # always get that much for cirrusci macOS instances
     BUILD_JOBS: $CPUS
-    TEST_JOBS: $CPUS # already fast enough to not be worth tuning
+    # Test performance regresses noticably when using all cores. 8 seems to
+    # work OK. See
+    # https://postgr.es/m/20220927040208.l3shfcidovpzqxfh%40awork3.anarazel.de
+    TEST_JOBS: 8
 
     CIRRUS_WORKING_DIR: ${HOME}/pgsql/
     CCACHE_DIR: ${HOME}/ccache