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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 0F828C43441 for ; Sat, 10 Nov 2018 00:32:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C92E520883 for ; Sat, 10 Nov 2018 00:32:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C92E520883 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728253AbeKJKPO (ORCPT ); Sat, 10 Nov 2018 05:15:14 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:34176 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727210AbeKJKPN (ORCPT ); Sat, 10 Nov 2018 05:15:13 -0500 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::cf9]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id E168214C09564; Fri, 9 Nov 2018 16:32:11 -0800 (PST) Date: Fri, 09 Nov 2018 16:32:11 -0800 (PST) Message-Id: <20181109.163211.1071335811309003117.davem@davemloft.net> To: robh@kernel.org Cc: frowand.list@gmail.com, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org Subject: Re: [PATCH 3/8] sparc: prom: use property "name" directly to construct node names From: David Miller In-Reply-To: References: <20181107223151.14991-4-robh@kernel.org> <20181108.191320.1503108955211963619.davem@davemloft.net> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Fri, 09 Nov 2018 16:32:12 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rob Herring Date: Fri, 9 Nov 2018 07:02:46 -0600 > On Thu, Nov 8, 2018 at 9:13 PM David Miller wrote: >> >> From: Rob Herring >> Date: Wed, 7 Nov 2018 16:31:46 -0600 >> >> > In preparation to remove direct accesses to the device_node.name >> > pointer, retrieve the node name from the "name" property instead. >> > >> > Cc: "David S. Miller" >> > Cc: sparclinux@vger.kernel.org >> > Signed-off-by: Rob Herring >> >> On some 32-bit sparcs, the OF runs in non-cached memory. >> >> Sucking in the OF device tree take a signficant amount of the >> boot time on such systems. >> >> And these changes are going to make it even slower. >> >> Please just put a wrapper around dp->name or whatever and use that, >> instead of making more get property OF calls which can be very >> expensive. > > It's not making calls into OF. It is retrieving the property from the > kernel's copy of the DT (allocated by memblock). So the only > difference is we have to walk the struct property list to find "name". > That's perhaps offset by the fact that we'll be doing one less > property retrieval from OF when this is all done. Right now, we > retrieve "name" from OF twice per node. Ok, now I understand, thanks.