From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B903BC04AB5 for ; Mon, 3 Jun 2019 23:50:59 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 72E1F26329 for ; Mon, 3 Jun 2019 23:50:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 72E1F26329 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45HsJK4vDvzDqWx for ; Tue, 4 Jun 2019 09:50:57 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=permerror (mailfrom) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45HsGs44TKzDqH4 for ; Tue, 4 Jun 2019 09:49:41 +1000 (AEST) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x53NnXcT016185; Mon, 3 Jun 2019 18:49:33 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id x53NnWCZ016184; Mon, 3 Jun 2019 18:49:32 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Mon, 3 Jun 2019 18:49:32 -0500 From: Segher Boessenkool To: Benjamin Herrenschmidt Subject: Re: [PATCH kernel] prom_init: Fetch flatten device tree from the system firmware Message-ID: <20190603234932.GR31586@gate.crashing.org> References: <20190501034221.18437-1-aik@ozlabs.ru> <20190530193736.GC31586@gate.crashing.org> <43f037c57eed8ad2175470c940917dced947bb70.camel@kernel.crashing.org> <20190602232330.GN31586@gate.crashing.org> <7fc6cd5e-ddd6-4028-b4ef-7bdcd6db69d0@ozlabs.ru> <32063141651fd502c8ce94be19cb5c5330ce39bd.camel@kernel.crashing.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <32063141651fd502c8ce94be19cb5c5330ce39bd.camel@kernel.crashing.org> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , linuxppc-dev@lists.ozlabs.org, Suraj Jitindar Singh , David Gibson Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Jun 04, 2019 at 07:18:42AM +1000, Benjamin Herrenschmidt wrote: > Yes we could make property fetching faster but mostly by creating a new > bulk interface which is quite a bit of work, a new API, and will in > practice not be used for anything other than creating the FDT. In that > case, nothing will beat in performance having OF create the FDT itself > based on its current tree. And that will change the whole boot protocol, the interaction between OF and its client, which is a much bigger change, not conceptually trivial at all. Copying all properties at once is, which is why I suggested it. It would take away the opposition to your patch. Segher