From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andy Wingo <wingo@igalia.com>
Subject: Re: Making evaluations faster
Date: Tue, 19 Dec 2017 11:56:28 +0100
Message-ID: <87y3lz56lf.fsf@igalia.com>
References: <87po7b6qb2.fsf@gnu.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Return-path: <guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:46208)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <wingo@igalia.com>) id 1eRFaI-00056c-6E
	for guix-devel@gnu.org; Tue, 19 Dec 2017 05:57:19 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <wingo@igalia.com>) id 1eRFaF-0007ho-4k
	for guix-devel@gnu.org; Tue, 19 Dec 2017 05:57:18 -0500
In-Reply-To: <87po7b6qb2.fsf@gnu.org> ("Ludovic =?utf-8?Q?Court=C3=A8s=22'?=
	=?utf-8?Q?s?= message of "Tue, 19 Dec 2017 10:05:21 +0100")
List-Id: "Development of GNU Guix and the GNU System distribution."
	<guix-devel.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/guix-devel>,
	<mailto:guix-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/guix-devel/>
List-Post: <mailto:guix-devel@gnu.org>
List-Help: <mailto:guix-devel-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/guix-devel>,
	<mailto:guix-devel-request@gnu.org?subject=subscribe>
Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org
Sender: "Guix-devel" <guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org>
To: Ludovic =?utf-8?Q?Court=C3=A8s?= <ludo@gnu.org>
Cc: guix-devel <guix-devel@gnu.org>

On Tue 19 Dec 2017 10:05, ludo@gnu.org (Ludovic Court=C3=A8s) writes:

> I=E2=80=99ve been looking for ways to make evaluations (computing the der=
ivation
> of every package for every supported architecture, like Hydra and
> Cuirass do) faster.
>
> I measured evaluations with:
>
>   rm -rf /tmp/cache hydra-jobs.scm
>   mkdir /tmp/cache
>   XDG_CACHE_HOME=3D/tmp/cache make hydra-jobs.scm
>
> Currently build-aux/hydra/gnu-system.scm, which performs the evaluation
> work, turns on auto-compile such that every Guix module gets compiled.
>
> I measured with 2.2.3 the impact of turning off auto-compilation for
> everything but the core modules (meaning that package modules get
> interpreted instead) and surprisingly, this is slower than compiling
> everything:
>
>   * 2.2.3, auto-compile everything minus (system base compile) & co.
>
>   1362.79user 3.35system 20:59.40elapsed 108%CPU (0avgtext+0avgdata 12014=
44maxresident)k
>   0inputs+203560outputs (0major+285018minor)pagefaults 0swaps
>
>   * 2.2.3, auto-compile (guix packages) only
>
>   2462.05user 3.69system 39:26.05elapsed 104%CPU (0avgtext+0avgdata 21215=
32maxresident)k
>   128inputs+36568outputs (0major+242281minor)pagefaults 0swaps
>
>   * 2.2.3, auto-compile ((guix packages) (guix build-system gnu) (guix do=
wnload))
>
>   2364.22user 3.21system 37:44.45elapsed 104%CPU (0avgtext+0avgdata 20614=
96maxresident)k
>   256inputs+41800outputs (0major+236514minor)pagefaults 0swaps
>
> I guess the extra source properties that are retained when evaluating
> account for part the space and time overhead, but I=E2=80=99m not sure th=
is
> explains everything.
>
> Andy, what do you think of this?

I have literally no idea :)  This isn't really enough information for me
to understand things.  I guess my biggest question would be, why are you
using the auto-compile infrastructure?  Why wouldn't you compile the
things you want to compile and otherwise turn off auto-compilation?

Andy