From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp0 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id UPfqHWqM2F9mawAA0tVLHw (envelope-from ) for ; Tue, 15 Dec 2020 10:14:02 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp0 with LMTPS id MCnEGWqM2F9TVQAA1q6Kng (envelope-from ) for ; Tue, 15 Dec 2020 10:14:02 +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 8E5C6940222 for ; Tue, 15 Dec 2020 10:14:01 +0000 (UTC) Received: from localhost ([::1]:44234 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kp7LE-0000DZ-9g for larch@yhetil.org; Tue, 15 Dec 2020 05:14:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:39276) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kp7L6-0000DR-47 for guix-devel@gnu.org; Tue, 15 Dec 2020 05:13:52 -0500 Received: from relay10.mail.gandi.net ([217.70.178.230]:41349) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kp7L3-0001U0-Gr; Tue, 15 Dec 2020 05:13:51 -0500 Received: from bababa (lfbn-idf2-1-709-87.w86-247.abo.wanadoo.fr [86.247.16.87]) (Authenticated sender: mail@ambrevar.xyz) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 8E84F240018; Tue, 15 Dec 2020 10:13:44 +0000 (UTC) From: Pierre Neidhardt To: =?utf-8?Q?Nicol=C3=B2?= Balzarotti , Ludovic =?utf-8?Q?Court=C3=A8s?= , guix-devel Subject: Re: When substitute download + decompression is CPU-bound In-Reply-To: <87k0tjo085.fsf@guixSD.i-did-not-set--mail-host-address--so-tickle-me> References: <87im94qbby.fsf@gnu.org> <87sg88ngd1.fsf@guixSD.i-did-not-set--mail-host-address--so-tickle-me> <871rfrld59.fsf@ambrevar.xyz> <87pn3bo117.fsf@guixSD.i-did-not-set--mail-host-address--so-tickle-me> <87im93bdj1.fsf@ambrevar.xyz> <87k0tjo085.fsf@guixSD.i-did-not-set--mail-host-address--so-tickle-me> Date: Tue, 15 Dec 2020 11:13:43 +0100 Message-ID: <87a6ufbcmg.fsf@ambrevar.xyz> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Received-SPF: pass client-ip=217.70.178.230; envelope-from=mail@ambrevar.xyz; helo=relay10.mail.gandi.net X-Spam_score_int: 0 X-Spam_score: -0.1 X-Spam_bar: / X-Spam_report: (-0.1 / 5.0 requ) BAYES_00=-1.9, FROM_SUSPICIOUS_NTLD=0.499, PDS_OTHER_BAD_TLD=1.999, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: , Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Migadu-Flow: FLOW_IN X-Migadu-Spam-Score: -4.41 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: 8E5C6940222 X-Spam-Score: -4.41 X-Migadu-Scanner: scn0.migadu.com X-TUID: F5Q5S110u66c --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Nicol=C3=B2 Balzarotti writes: > If you download multiple files at a time, you might end up decompressing > them simultaneously. Plzip won't help then on a dual core machine, > where you might end up being cpu bound again then. Is this right? > > If it is, reducing the overall cpu usage seems to be a better approach > in the long term. An answer to this may be in pipelining the process. The parallel downloads would feed the archives to the pipeline and the parallel decompressor would pop the archives out of the pipeline one by one. If I'm not mistaken, this should yield optimal results regardless of the network or CPU performance. =2D-=20 Pierre Neidhardt https://ambrevar.xyz/ --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQFGBAEBCAAwFiEEUPM+LlsMPZAEJKvom9z0l6S7zH8FAl/YjFcSHG1haWxAYW1i cmV2YXIueHl6AAoJEJvc9Jeku8x/9ZQH/1dT9XiNFfW1UKM31SJGKE++nl6Ph9md 78etMTbcD/XkTuMYsY2dYXI+efAKrB84n4mrPX/vt1hdfpDrWbOlb2tBeYOKi+mW RYP3Ynpn+l/zaC9QKeWJ0WRMGT2zfJ4PrqCUk/mGzD+oTaOdnfv1KaGXBcSBokVO Iv7Fb1Tl0m5FqLkJRx4woV0GxTagWAzPT/mkGqzHRTqGzn/K8fbxauCTFsSqSUb9 GIKo4UWDyZ0Q4ixD+u851d3gvF8zO1sEBu02Bav1tHtVSVWrka1R1Xk+Msu+Ey7Y hhrTkarPXEV5sQwT+5QsaZBOTsQh/P+DqSYAp8Q6aeY39zZ76hBnu6Q= =TfS7 -----END PGP SIGNATURE----- --=-=-=--