From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp0 ([2001:41d0:2:bcc0::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms0.migadu.com with LMTPS id 0MneIs3smGC+HgAAgWs5BA (envelope-from ) for ; Mon, 10 May 2021 10:20:29 +0200 Received: from aspmx1.migadu.com ([2001:41d0:2:bcc0::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp0 with LMTPS id yDqYHs3smGAkPAAA1q6Kng (envelope-from ) for ; Mon, 10 May 2021 08:20:29 +0000 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id 341D71167E for ; Mon, 10 May 2021 10:20:29 +0200 (CEST) Received: from localhost ([::1]:42914 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lg19Q-0004uR-9D for larch@yhetil.org; Mon, 10 May 2021 04:20:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47634) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lg19I-0004u3-1I for guix-devel@gnu.org; Mon, 10 May 2021 04:20:20 -0400 Received: from flashner.co.il ([178.62.234.194]:41784) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lg19G-0006In-Bj; Mon, 10 May 2021 04:20:19 -0400 Received: from localhost (unknown [31.210.177.125]) by flashner.co.il (Postfix) with ESMTPSA id 91A6540349; Mon, 10 May 2021 08:20:15 +0000 (UTC) Date: Mon, 10 May 2021 11:20:10 +0300 From: Efraim Flashner To: Ludovic =?utf-8?Q?Court=C3=A8s?= Subject: Re: bug#47615: [PATCH 0/9] Add 32-bit powerpc support Message-ID: Mail-Followup-To: Ludovic =?utf-8?Q?Court=C3=A8s?= , 47615@debbugs.gnu.org, guix-devel@gnu.org References: <87zgxwsxsd.fsf@gnu.org> <87wnscdj0x.fsf_-_@gnu.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="Iu5Q/aLezd2QIYj3" Content-Disposition: inline In-Reply-To: <87wnscdj0x.fsf_-_@gnu.org> X-PGP-Key-ID: 0x41AAE7DCCA3D8351 X-PGP-Key: https://flashner.co.il/~efraim/efraim_flashner.asc X-PGP-Fingerprint: A28B F40C 3E55 1372 662D 14F7 41AA E7DC CA3D 8351 Received-SPF: pass client-ip=178.62.234.194; envelope-from=efraim@flashner.co.il; helo=flashner.co.il X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: guix-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: guix-devel@gnu.org, 47615@debbugs.gnu.org Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Migadu-Flow: FLOW_IN ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1620634829; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references:list-id:list-help:list-unsubscribe: list-subscribe:list-post; bh=Vw5sN2Lui0MpLabNEppq0ghbSJw+K2aH5fcobopZkkI=; b=W7hJUYqT/Ia/tHnAxw3oVCuS/SrHeKLdOTl2zRdFdesAZ5TOrV0fD/gADuBOr1eo12J5Dn 0NgdKhsBx4EGlodcUoZyE8OiDq0tkCpjYWn4/rFvbMO5vbMYsLpLElnaTLTIOm2+hdrIjF BNQGfvqYVrifrQ7cORLpgUs0vza51tg8gGT8Eb6xYxgNKdIvXIHiCqFs57EBax/nBlGOSM fYXfgRaWo41WlappRVCDf3DgCaB0tf5TaY4VNjDxfgcM6e/7RAMJtnb1YX0kNoL/lnk+fX D6OJh8OXqeQfpXIlbjgnDlbPRTwcojb9mz1FZyl99TgZfNycTPHc8AgIE0pxOg== ARC-Seal: i=1; s=key1; d=yhetil.org; t=1620634829; a=rsa-sha256; cv=none; b=sh999cd/lnOnNGk8UcLifBoQGQFEmnnGhJ4INMJTSyOb7mCvdJeGl78otsB312BPW0t4hF SQTU+euoN3PjOwmKQenGKBQ/ERSt1nhdTPCSg66oTi+Jwzy+YCNMjXGvgUSvj2z/W8IFI2 gc09aE03fxEzPvh8qWtItX2Kp6xjKGRse9mBlVtegj6rasFd22ipYx8E40cOO1ufba2y21 /hrDrAJ+gPzXx2zWZZwzAOVTJ502CBXeGmUuvRTXbEosCuJCu0xweX87sB/RJJF2gD56f/ 8hmIZ0narnos5jHyJB+/PZpxeI+r4s9oReeDSjrgY76vWOiBVluqnXb+G4y3ww== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=none; dmarc=none; spf=pass (aspmx1.migadu.com: domain of guix-devel-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-devel-bounces@gnu.org X-Migadu-Spam-Score: -4.05 Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=none; spf=pass (aspmx1.migadu.com: domain of guix-devel-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-devel-bounces@gnu.org X-Migadu-Queue-Id: 341D71167E X-Spam-Score: -4.05 X-Migadu-Scanner: scn0.migadu.com X-TUID: d9ER+BKO8IqU --Iu5Q/aLezd2QIYj3 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 06, 2021 at 04:38:38PM +0200, Ludovic Court=C3=A8s wrote: > Hi Efraim, >=20 > Efraim Flashner skribis: >=20 > > On Sat, Apr 17, 2021 at 06:04:02PM +0200, Ludovic Court=C3=A8s wrote: >=20 > [...] >=20 > >> 3. OTOH, what will be the status of this architecture? I don=E2=80= =99t think > >> new 32-bit PPC hardware is being made (right?), so I guess we > >> probably won=E2=80=99t have substitutes for that architecture. T= hat means > >> it won=E2=80=99t be supported at the same level as other architec= tures and > >> may quickly suffer from bitrot. > > > > I don't know about new 32-bit powerpc hardware, I think it's only being > > newly created for the embedded and networking space. As far as operating > > systems with support=C2=B9 Ad=C3=A9lie Linux is the only one I know tha= t's > > actually targeting the machines. > > > > I found that emulation on my desktop (Ryzen 3900XT, 24 threads) is > > faster than building on native hardware (1 core, 1.5GB of RAM, original > > 4200 RPM disk), edging it out on single threaded compiling and doing > > great when it comes to using multiple cores and parallel builds. > > Ignoring how to create an OS image if we just targeted, say, mesa and > > maybe one or two other packages, we could have a core set which doesn't > > change regularly and won't take up too much emulated build time but will > > save days of compile time. >=20 > [...] >=20 > > The fear of bit-rot is real and I think we should mention in the manual > > (when I actually write the section) that support is best-effort with > > minimal substitutes. >=20 > I feel like =E2=80=9Cbest-effort with minimal substitutes=E2=80=9D is alr= eady more than > I=E2=80=99d be willing to commit to as a maintainer. I have also learned that 'best effort' is a grey area in other circles; does it mean you'll move mountains and spare no expense (The Best Effort!=E2=84=A2) or that you'll give it a shot but make no promises. I definitely meant the second. > We just added POWER9, for which we have actual hardware, and even > getting to this minimal state where we provide a binary tarball required > quite some effort. >=20 > Doing the same with 32-bit PowerPC would require us to set up emulation; > we wouldn=E2=80=99t even have real hardware. >=20 > All in all, my preference would be to take the patches but not mention > PowerPC 32-bit support anywhere, or at least, not provide substitutes > and binary installation tarball. IOW, few people would know whether it > actually works :-) but tinkerers could still play with it. >=20 > WDYT? >=20 > Ludo=E2=80=99. How about changing the mips64el documentation to say that there is minimal support for the two architectures, with no substitutes, and may be fun for tinkerers with the hardware. Then we could also change the check in the guix.m4 to add mips64el-linux as supported in case anyone does actually want to play with it. Current text: @item mips64el-linux (deprecated)=C2=AC little-endian 64-bit MIPS processors, specifically the Loongson series, n32 ABI, and Linux-Libre kernel. This configuration is no longer fully supported; in particular, there is no ongoing work to ensure that this architecture still works. Should someone decide they wish to revive this architecture then the code is still available. Proposed text: @item Alternative architectures In addition to architectures which are actually supported there are a few formally unsupported architectures which may be of interested to tinkerers. Namely mips64el-linux, little-endian 64-bit MIPS processors, specifically the Loongson series, n32 ABI, and powerpc-linux, big-endian 32-bit POWER processors, specifically the PowerPC 74xx series. There are no installation tarballs, substitutes or promises that these architectures are functional. And then I'd move it lower than the powerpc64le-linux entry. --=20 Efraim Flashner =D7=90=D7=A4=D7=A8=D7=99=D7=9D = =D7=A4=D7=9C=D7=A9=D7=A0=D7=A8 GPG key =3D A28B F40C 3E55 1372 662D 14F7 41AA E7DC CA3D 8351 Confidentiality cannot be guaranteed on emails sent or received unencrypted --Iu5Q/aLezd2QIYj3 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEoov0DD5VE3JmLRT3Qarn3Mo9g1EFAmCY7LcACgkQQarn3Mo9 g1HkoQ//YjjzjmOACwMIhM8dnpsOogCvN5l7q93nUal3SiQmqdVX1EzjQedVbdOF go8arQtauh8tPuhNCS0MeNN+khUalWsiiz4j8TfC/sDs4L6SwN8cfiqUZC42Ax8e hsy1E8y+rjKhe26+zagaHrZeoGoNTft3vXwSjNusmn6x9aG8wVsvOsjEwYfauxdd en5RKWsVuLL523RGKPFA20w/0W52yneYaBj6UeljTP3xBgoyV6kDMay+fCDHk2oj GdmPI7p1Rrs8Pbxh+6h6xhH1v/8EBkHrOx6+RIPUyjqhuyKtNIFz0IJ5aIPdc9dG ahxk8TfiPnfORu7qXlAKz1E8OJAb03S87qsVnwHww0TsKUqB4/XFY0SyMOIxqoJP aycFoGCQWWPYVTNYxtJtsCn9cFRIdzD+uuoGEfDHlkIXOXIdMEBewWqmmV1Ncye8 5pEHPSeP59q6r+FUilwSBZpz+gNRL8QBRubdSyrSE6wHd8jqcv1ExzBmeTjXz9KR 2wL7/ezK+xTxeYMHFog97cGpxkpPymSXlT0Fv8wbM5XSQqg7QdO3cbyd0pvBtsYF xBhkVo+fLFharWE5LrB6yYeTEqg21Nik3fOgsLCjgmZJtIeRhM6lFyK+pD7Sts5E 6lme8KifntMv2yuABikO85Joi7qJyzRWQpq21cvbBSQDmxOFFd0= =jmpg -----END PGP SIGNATURE----- --Iu5Q/aLezd2QIYj3--