From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from xry111.site (xry111.site [IPv6:2001:470:683e::1]) by sourceware.org (Postfix) with ESMTPS id 6CF6D3858C39 for ; Tue, 8 Nov 2022 07:33:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6CF6D3858C39 Authentication-Results: sourceware.org; dmarc=pass (p=reject dis=none) header.from=xry111.site Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=xry111.site DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=xry111.site; s=default; t=1667892837; bh=KUzNMLxn6UTlNsi61l0JcDqYyEPKFuE+wEQZr1ZPC30=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=cKlO79DaCLa0CduKPyQDLFnEW4o66aqBIlVJMT2mToFhOSmHFAKCSdaozF0Z1V7EZ RHIWN6Y56gx+MTO6atF011Ks0ud4Y4b4MtcVR8J341NRhFHNVrWYMa75oApYx9uCiw T/qU3Mndl5RfJcNH0U+YpEQGHc2oyXIqSYU3BiW8= Received: from localhost.localdomain (xry111.site [IPv6:2001:470:683e::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-384) server-digest SHA384) (Client did not present a certificate) (Authenticated sender: xry111@xry111.site) by xry111.site (Postfix) with ESMTPSA id 324CE66857; Tue, 8 Nov 2022 02:33:56 -0500 (EST) Message-ID: <6e8d39e1e3e9d6ce5f0be5781023127187bcb995.camel@xry111.site> Subject: Re: [PATCH] maintainer-scripts/gcc_release: compress xz in parallel From: Xi Ruoyao To: Sam James , gcc-patches@gcc.gnu.org Cc: Gerald Pfeifer , Jakub Jelinek , Jeff Law Date: Tue, 08 Nov 2022 15:33:54 +0800 In-Reply-To: <20221108071438.2523863-1-sam@gentoo.org> References: <20221108071438.2523863-1-sam@gentoo.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.46.0 MIME-Version: 1.0 X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FROM_SUSPICIOUS_NTLD,LIKELY_SPAM_FROM,PDS_OTHER_BAD_TLD,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: On Tue, 2022-11-08 at 07:14 +0000, Sam James via Gcc-patches wrote: > 1. This should speed up decompression for folks, as parallel xz > =C2=A0=C2=A0 creates a different archive which can be decompressed in par= allel. >=20 > =C2=A0=C2=A0 Note that this different method is enabled by default in a n= ew > =C2=A0=C2=A0 xz release coming shortly anyway (>=3D 5.3.3_alpha1). >=20 > =C2=A0=C2=A0 I build GCC regularly from the weekly snapshots > =C2=A0=C2=A0 and so the decompression time adds up. >=20 > 2. It should speed up compression on the webserver a bit. >=20 > =C2=A0=C2=A0 Note that -T0 won't be the default in the new xz release, > =C2=A0=C2=A0 only the parallel compression mode (which enables parallel > =C2=A0=C2=A0 decompression). >=20 > =C2=A0=C2=A0 -T0 detects the number of cores available. >=20 > =C2=A0=C2=A0 So, if a different number of threads is preferred, it's fine > =C2=A0=C2=A0 to set e.g. -T2, etc. 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. --=20 Xi Ruoyao School of Aerospace Science and Technology, Xidian University