On Tue, Mar 14, 2023 at 3:56 AM Bastian Germann <bage@xxxxxxxxxxxxx> wrote: > > Am 13.03.23 um 18:59 schrieb Masahiro Yamada: > > On Tue, Mar 14, 2023 at 2:10 AM Bastian Germann <bage@xxxxxxxxxxxxx> wrote: > >> > >> Currently, the only way to build the deb-pkg generated package parallely > >> is adding -jN to the MAKEFLAGS environment variable. The package ignores > >> the usual parallel build option that is described in Debian Policy §4.9.1. > > > > > > > > "dpkg-buildpackage -b -j16" worked for me. > > This ends up in DEB_BUILD_OPTIONS=parallel=16 being set and the call: > /usr/bin/make -f ./Makefile ARCH=x86 KERNELRELEASE=6.3.0-rc2 KBUILD_BUILD_VERSION=1 olddefconfig all "dpkb-buildpackage -j<N>" sets not only DEB_BUILD_OPTIONS but also MAKEFLAGS. This is clearly explained in "man dpkb-buildpackage". -j, --jobs[=jobs|auto] ... Will add itself to the MAKEFLAGS environment variable, which should cause all subsequent make invocations to inherit the option, thus forcing the parallel setting on the packaging ... Your statement sounds like 'MAKEFLAGS=-j<N> dpkg-buildpackage' is the only way to build packages in parallel. Apparently, dpkg-buildpackage provides a much shorter way and invokes internal Make in parallel. > > So it is not used to run the actual build, just the top level `make -f debian/rules` invocation. > You can set --jobs-force=16, which ends up in MAKEFLAGS but the point of the patch is that one can use > the usual way of parallelizing. What is the "usual" way in this context? Do you mean 'DEB_BUILD_OPTIONS=parallel=16 dpkg-buildpackage -b' is the usual way for parallel building? If so, I agree. This patch caters to this case. But, I think your code should go to debian/rules instead of scripts/package/deb-build-option. Kbuild's "make clean" works much faster with the parallel option. Also, the commit description should explain the benefit of this patch. > > Side note: Without the patch, the build is run with -j1 regardless of being called from the Linux Makefile > or dpkg-buildpackage. Try: $ make deb-pkg -j16 and $ dpkg-buildpackage -b -j16 Both run the package building in parallel. You see a big difference in build speed w/wo the -j option. (and the build logs are interleaved, since they are emitted by multiple threads) -- Best Regards Masahiro Yamada
