Fix the parallelism and load issues.

This is done by using two new environment variables:
+ CI_PARALLELISM, the number of cores available per CI job.
+ CI_LOAD_LIMIT, the maximum authorized load limit (total number of
  cores on the machine).

Both of these are set in the respective /etc/gitlab-runner/config.toml
for each machine, in the `[[runners]]` section. See:
https://docs.gitlab.com/runner/configuration/advanced-configuration.html#the-runners-section

.gitlab-ci.yml

@@ -25,7 +25,7 @@ stages:
  EXTRA_CMAKE_FLAGS: ""
 
 .before_script_template: &default_before_script
- - export NUM_CORES=4
+ - export NUM_CORES=${CI_PARALLELISM}
  - export OMP_NUM_THREADS=${NUM_CORES}
  - export CUDA_VISIBLE_DEVICES=0
 
@@ -58,7 +58,7 @@ stages:
  -DGINKGO_BUILD_OMP=${BUILD_OMP} -DGINKGO_BUILD_CUDA=${BUILD_CUDA}
  -DGINKGO_BUILD_HIP=${BUILD_HIP}
  -DGINKGO_BUILD_TESTS=ON -DGINKGO_BUILD_EXAMPLES=ON
- - ninja -j${NUM_CORES} -l `nproc`
+ - ninja -j${NUM_CORES} -l${CI_LOAD_LIMIT}
  dependencies: []
  except:
  - schedules
@@ -83,7 +83,7 @@ stages:
  -DGINKGO_BUILD_OMP=${BUILD_OMP} -DGINKGO_BUILD_CUDA=${BUILD_CUDA}
  -DGINKGO_BUILD_HIP=${BUILD_HIP}
  -DGINKGO_BUILD_TESTS=ON -DGINKGO_BUILD_EXAMPLES=ON
- - ninja -j${NUM_CORES} -l `nproc` install
+ - ninja -j${NUM_CORES} -l${CI_LOAD_LIMIT} install
  - |
  (( $(ctest -N | tail -1 | sed 's/Total Tests: //') != 0 )) || exit 1
  - ctest -V
@@ -864,7 +864,7 @@ fineci-benchmark-build:
  -DGINKGO_BUILD_HIP=${BUILD_HIP} \\
  -DGINKGO_BUILD_TESTS=OFF -DGINKGO_BUILD_EXAMPLES=OFF \\
  -DGINKGO_BUILD_BENCHMARKS=ON
- make -j4
+ make -j${CI_PARALLELISM}
  EOT
  dependencies: []
  only:

cmake/CTestScript.cmake

@@ -130,8 +130,12 @@ endif()
 include(ProcessorCount)
 ProcessorCount(PROC_COUNT)
 if(NOT PROC_COUNT EQUAL 0)
- if (PROC_COUNT GREATER 10)
- set(PROCT_COUNT 10)
+ if (defined ENV{CI_PARALLELISM})
+ set(PROC_COUNT "$ENV{CI_PARALLELISM}")
+ elseif(PROC_COUNT LESS 4)
+ set(PROC_COUNT 1)
+ else()
+ set(PROC_COUNT 4)
  endif()
  if(NOT WIN32)
  set(CTEST_BUILD_FLAGS "-j${PROC_COUNT}")