From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.gentoo.org (mail.gentoo.org [IPv6:2001:470:ea4a:1:5054:ff:fec7:86e4]) by sourceware.org (Postfix) with ESMTP id 3419A3857405 for ; Tue, 8 Nov 2022 08:54:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3419A3857405 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gentoo.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gentoo.org Content-Type: multipart/signed; boundary="Apple-Mail=_604286A5-0826-4B27-97B7-9C1AF5BA855F"; protocol="application/pgp-signature"; micalg=pgp-sha512 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3731.200.110.1.12\)) Subject: Re: [PATCH] maintainer-scripts/gcc_release: compress xz in parallel From: Sam James In-Reply-To: Date: Tue, 8 Nov 2022 08:53:57 +0000 Cc: Xi Ruoyao , gcc-patches@gcc.gnu.org, Gerald Pfeifer , Jeff Law Message-Id: <2DD8DF6B-0280-488E-9B02-E2CE815517CD@gentoo.org> References: <20221108071438.2523863-1-sam@gentoo.org> <6e8d39e1e3e9d6ce5f0be5781023127187bcb995.camel@xry111.site> <9E6C1D21-0F77-4740-A9D3-9EE415D0AABD@gentoo.org> To: Jakub Jelinek X-Mailer: Apple Mail (2.3731.200.110.1.12) X-Spam-Status: No, score=-4.5 required=5.0 tests=BAYES_00,JMQ_SPF_NEUTRAL,KAM_DMARC_STATUS,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: --Apple-Mail=_604286A5-0826-4B27-97B7-9C1AF5BA855F Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii > On 8 Nov 2022, at 08:52, Jakub Jelinek wrote: > > On Tue, Nov 08, 2022 at 07:40:02AM +0000, Sam James wrote: >>> On 8 Nov 2022, at 07:33, Xi Ruoyao wrote: >>> I'm wondering if running xz -T0 on different machines (with different >>> core numbers) may produce different compressed data. The difference can >>> cause trouble distributing checksums. >>> >> >> Your question is a good one - xz -T0 produces different results to xz -T1 >> but: >> 1. The tarballs for GCC are only created on one machine and aren't >> created repeatedly then compared with each other wrt mirroring; > > No, that is not the case. > While the snapshots are created on sourceware locally, GCC releases (and > release candidates) are typically created on some RM's local machine. We've misinterpreted each other. I mean the same tarball isn't then recreated repeatedly and different copies uploaded to mirrors. Obviously different machines may be used at different points. --Apple-Mail=_604286A5-0826-4B27-97B7-9C1AF5BA855F Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP -----BEGIN PGP SIGNATURE----- iNUEARYKAH0WIQQlpruI3Zt2TGtVQcJzhAn1IN+RkAUCY2oZJV8UgAAAAAAuAChp c3N1ZXItZnByQG5vdGF0aW9ucy5vcGVucGdwLmZpZnRoaG9yc2VtYW4ubmV0MjVB NkJCODhERDlCNzY0QzZCNTU0MUMyNzM4NDA5RjUyMERGOTE5MAAKCRBzhAn1IN+R kOv2AQDUfzDhnVoP5Qsbwkvl/OS12ZrWbuS1Ae6mAUhyx7Np4QEAkmBIqL3sBMPx 3AP/JYFvEMWe8iD9TymYodXSQEBD/go= =SVpx -----END PGP SIGNATURE----- --Apple-Mail=_604286A5-0826-4B27-97B7-9C1AF5BA855F--