From: Edd Barrett <edd@theunixzoo.co.uk>
Subject: Re: ports setting GOMAXPROCS
To: Theo Buehler <tb@theobuehler.org>
Cc: ports@openbsd.org, claudio@openbsd.org, edd@openbsd.org, kn@openbsd.org, lraab@openbsd.org, jsing@openbsd.org, stu@spacehopper.org
Date: Sun, 25 Jan 2026 11:36:20 +0000

No objections from me.

25 Jan 2026 10:50:19 Theo Buehler <tb@theobuehler.org>:

> Several go ports set GOMAXPROCs to MAKE_JOBS in MAKE_ENV. I think this
> is more brutal than intended and hinders more than it helps because per
> https://pkg.go.dev/runtime:
> 
>   The GOMAXPROCS variable limits the number of operating system threads
>   that can execute user-level Go code simultaneously
> 
> In my test bulk builds with go 1.26rc2, grafana takes more than half
> an hour to do its one slow compile/link/whatever step. I had one
> pathological bulk where it took 4000s.
> 
> jsing points out that it would be better to pass -p ${MAKE_JOBS} to
> the build/run/install commands, which the go module already adds to
> the MODGO_FLAGS.
> 
> -p n
>     the number of programs, such as build commands or
>     test binaries, that can be run in parallel.
>     The default is GOMAXPROCS, normally the number of CPUs available.
> 
> Now this doesn't seem entirely true in practice since I see the builds
> spawning a few processes more than one but I think this is acceptable
> given that it's only for a rather short time.
> 
> The below is my suggestion for reposurgeon, syncthing and grafana.
> syncthing might want to do the same in its hand-rolled test command.
> 
> There's another one in prometheus, but it looks slightly different.
> 
> Index: devel/reposurgeon/Makefile
> ===================================================================
> RCS file: /cvs/ports/devel/reposurgeon/Makefile,v
> diff -u -p -r1.20 Makefile
> --- devel/reposurgeon/Makefile  28 Jun 2025 00:36:32 -0000  1.20
> +++ devel/reposurgeon/Makefile  24 Jan 2026 22:52:33 -0000
> @@ -26,7 +26,7 @@ MODRUBY_RUNDEP=   No
> WRKSRC=        ${WRKDIST}
> WRKBUILD=  ${WRKDIST}
> MODGO_GOPATH=  ${MODGO_WORKSPACE}:${MODGO_PACKAGE_PATH}:${WRKSRC}/vendor
> -MAKE_ENV=  GOFLAGS=-v GOMAXPROCS=${MAKE_JOBS}
> +MAKE_ENV=  GOFLAGS=-v
> 
> FAKE_FLAGS=    mandir=man
> 
> Index: net/syncthing/Makefile
> ===================================================================
> RCS file: /cvs/ports/net/syncthing/Makefile,v
> diff -u -p -r1.76 Makefile
> --- net/syncthing/Makefile  17 Jan 2026 00:37:56 -0000  1.76
> +++ net/syncthing/Makefile  25 Jan 2026 10:16:37 -0000
> @@ -27,8 +27,6 @@ MODULES =     lang/go
> # so we package only these binaries.
> ST_CMDS =  syncthing stdiscosrv strelaysrv
> 
> -MAKE_ENV = GOMAXPROCS=${MAKE_JOBS}
> -
> pre-build:
>     ${SUBST_CMD} ${WRKSRC}/cmd/syncthing/main.go
> 
> @@ -37,7 +35,7 @@ pre-build:
> # without quic support obviously). When you do that, some more tests will fail.
> do-build:
> .for cmd in ${ST_CMDS}
> -   cd ${WRKSRC} && ${MODGO_CMD} run build.go -version v${V} \
> +   cd ${WRKSRC} && ${MODGO_CMD} run ${MODGO_FLAGS} build.go -version v${V} \
>         -no-upgrade install ${cmd}
> .endfor
> 
> Index: sysutils/grafana/Makefile
> ===================================================================
> RCS file: /cvs/ports/sysutils/grafana/Makefile,v
> diff -u -p -r1.56 Makefile
> --- sysutils/grafana/Makefile   19 Dec 2025 02:30:03 -0000  1.56
> +++ sysutils/grafana/Makefile   25 Jan 2026 10:06:46 -0000
> @@ -35,7 +35,6 @@ WANTLIB +=    c pthread
> 
> MODGO_GO111MODULE = on
> MODGO_FLAGS += -ldflags="-w -X main.version=$V"
> -MAKE_ENV = GOMAXPROCS=${MAKE_JOBS}
> 
> do-build:
>     mkdir -p ${WRKDIR}/go/src/github.com/grafana