feat: parallelize spack install (i.e. build) of uncached packages

Change-Id: Ibb9cb13002dcfe159e93cd1676cb7d5e142ff328

bin/yashchiki

@@ -120,7 +120,7 @@ parser.add_argument(
 # optional options
 parser.add_argument(
     "-j", "--jobs", type=int, default=1,
-    help="Number of parallel jobs to use when concurt execution of tasks is available.")
+    help="Number of parallel jobs to use when concurrent execution of tasks is available.")
 parser.add_argument(
     "--debug", action="store_true",
     help="Enable debug-level logging.")

lib/yashchiki/install_spack_packages.sh

@@ -14,6 +14,8 @@ cd "$HOME"
 install_from_buildcache "${spack_packages[@]+"${spack_packages[@]}"}"
 
 echo "INSTALLING PACKAGES"
+# heurisitic: let's use -j 8 typically… (and parallelize spack builds)
+SPACK_INSTALL_PARALLELISM=1 # ECM (2024-09-16): disabled $(( (${YASHCHIKI_JOBS} - 8) / 8 + 1))
 for package in "${spack_packages[@]+"${spack_packages[@]}"}"; do
     # Disable cache because we already installed from build cache.
     # Also there is a bug that when `--no-cache` is not specified, install will
@@ -24,8 +26,12 @@ for package in "${spack_packages[@]+"${spack_packages[@]}"}"; do
         echo "ERROR: Failed to concretize ${package} for install." >&2
         exit 1
     fi
-    echo "Installing: ${package}" >&2
-    ${MY_SPACK_CMD} "${SPACK_ARGS_INSTALL[@]+"${SPACK_ARGS_INSTALL[@]}"}" install --fresh --no-cache --show-log-on-error --file "${specfile}"
+
+    echo "Installing: ${package} (parallelism factor ${SPACK_INSTALL_PARALLELISM})" >&2
+    for i in `seq 1 ${SPACK_INSTALL_PARALLELISM}`; do
+        (nohup ${MY_SPACK_CMD} "${SPACK_ARGS_INSTALL[@]+"${SPACK_ARGS_INSTALL[@]}"}" install -j $(( (${YASHCHIKI_JOBS} - ${SPACK_INSTALL_PARALLELISM}) / ${SPACK_INSTALL_PARALLELISM} + 1 )) --fresh --no-cache --show-log-on-error --file "${specfile}" | sed -e "s:^:[${package}-${i}] :g") &
+    done
+    wait
 done
 
 # create the filesystem views (exposed via singularity --app option)