make -j $(expr $(nproc) / 2)

docker/Dockerfile

@@ -32,7 +32,7 @@ RUN git clone --depth=1 https://github.com/mikebrady/alac
 WORKDIR /alac
 RUN autoreconf -i
 RUN ./configure
-RUN make
+RUN make -j $(expr $(nproc) / 2)
 RUN make install
 WORKDIR /
 ##### ALAC END #####
@@ -44,7 +44,7 @@ RUN git clone --depth=1 -b "$NQPTP_BRANCH" https://github.com/mikebrady/nqptp
 WORKDIR /nqptp
 RUN autoreconf -i
 RUN ./configure
-RUN make
+RUN make -j $(expr $(nproc) / 2)
 WORKDIR /
 ##### NQPTP END #####
 
@@ -62,7 +62,7 @@ RUN CFLAGS="-O3" CXXFLAGS="-O3" ../configure --sysconfdir=/etc --with-alsa --wit
         --with-airplay-2 --with-metadata --with-dummy --with-pipe --with-dbus-interface \
         --with-stdout --with-mpris-interface --with-mqtt-client \
         --with-apple-alac --with-convolution --with-pw
-RUN make -j $(nproc)
+RUN make -j $(expr $(nproc) / 2)
 RUN DESTDIR=install make install
 WORKDIR /
 ##### SPS END #####