Limit the number of build jobs to 8 and link jobs to 4 for PowerPC.  This should help reduce the OOM build problems.
diff --git a/ci/build.gitlab-ci.yml b/ci/build.gitlab-ci.yml
index 073212a..edfd985 100644
--- a/ci/build.gitlab-ci.yml
+++ b/ci/build.gitlab-ci.yml
@@ -121,7 +121,7 @@
     EIGEN_CI_CXX_COMPILER: "g++-10"
     EIGEN_CI_CC_COMPILER: "gcc-10"
     EIGEN_TEST_CXX11: "on"
-    EIGEN_CI_ADDITIONAL_ARGS: "-DCMAKE_CXX_FLAGS='-DEIGEN_ALTIVEC_DISABLE_MMA'"
+    EIGEN_CI_ADDITIONAL_ARGS: "-DCMAKE_CXX_FLAGS='-DEIGEN_ALTIVEC_DISABLE_MMA' -DCMAKE_JOB_POOL_COMPILE:STRING=compile -DCMAKE_JOB_POOL_LINK:STRING=link '-DCMAKE_JOB_POOLS:STRING=compile=8;link=4'"
   tags:
     - eigen-runner
     - linux
@@ -135,6 +135,7 @@
     EIGEN_CI_CXX_COMPILER: "clang++-10"
     EIGEN_CI_CC_COMPILER: "clang-10"
     EIGEN_TEST_CXX11: "on"
+    EIGEN_CI_ADDITIONAL_ARGS: "-DCMAKE_JOB_POOL_COMPILE:STRING=compile -DCMAKE_JOB_POOL_LINK:STRING=link '-DCMAKE_JOB_POOLS:STRING=compile=8;link=4'"
   tags:
     - eigen-runner
     - linux