From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752159AbeA3S7c (ORCPT ); Tue, 30 Jan 2018 13:59:32 -0500 Received: from mail-pg0-f65.google.com ([74.125.83.65]:37012 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751475AbeA3S7a (ORCPT ); Tue, 30 Jan 2018 13:59:30 -0500 X-Google-Smtp-Source: AH8x2276wMben1MIOiKmxMHV6RfU2YLoBfSobUbFoPj1Tew8ObJ/FcQz/1wyKB5iarXFVB5d+W63cA== Subject: Re: [PATCH v2] of: use hash based search in of_find_node_by_phandle To: Chintan Pandya , robh+dt@kernel.org, devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org References: <1516955496-17236-1-git-send-email-cpandya@codeaurora.org> <2d877704-47c5-c1fc-1b89-976cd9b1ccaa@gmail.com> <7ebd275d-07ba-1972-011a-d05e53233a01@codeaurora.org> From: Frank Rowand Message-ID: Date: Tue, 30 Jan 2018 10:59:27 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <7ebd275d-07ba-1972-011a-d05e53233a01@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/30/18 00:04, Chintan Pandya wrote: >> (1) >> >> Can you point me to the driver code that is invoking >> the search? > There are many locations. Few of them being, > https://source.codeaurora.org/quic/la/kernel/msm-4.9/tree/drivers/of/irq.c?h=msm-4.9#n214 > https://source.codeaurora.org/quic/la/kernel/msm-4.9/tree/drivers/irqchip/irq-gic-v3.c?h=msm-4.9#n1107 > https://source.codeaurora.org/quic/la/kernel/msm-4.9/tree/drivers/clk/msm/msm-clock-controller.c?h=msm-4.9#n492 >> >> (2) >> >> And also the .dts devicetree source file that you are seeing >> large overhead with. > SDM670 DTS tree starts here. > https://source.codeaurora.org/quic/la/kernel/msm-4.9/tree/arch/arm64/boot/dts/qcom/sdm670.dtsi?h=msm-4.9 Thanks, I'm starting to get a picture of what you are facing. The file you point at is a .dtsi, not a .dts. There are quite a few sdm670*.dts files in that tree. Which one corresponds to the system you are working on? I picked a random one (sdm670-cdp.dts), but I need to be looking at the .dts that you are using to be able to ask reasonable questions instead of poking around in the dark. Also, when I clone that git tree there is not a valid HEAD. I picked what looked like a reasonable commit to checkout, but I would prefer to be looking at the same exact source that you are working with. Can you give me the commit id of the branch that you are working on? -Frank >> >> >> (3) -- this one is less important, but if the info is easily >>         available to you >> >> Sorry about dribbling out questions instead of all at once.... >> >> What is the hardware you are testing this on? > SDM670 >> Processor? > Kryo-300 Silver >> Cache size? > From DT, > L1 32KB (per CPU) > L2 128KB (per CPU) > L3 1MB (total) >> Memory size? > 6GB >> Processor frequency? > Max 1.7GHz for core 0. Not sure about boot time frequency. >> Any other attribute of the system that will help me understand >> the boot performance you are seeing? > I'm not able to profile of_find_node_by_phandle specifically as timers are > not up by then. So, just observing overall boot time for comparison. > > My recent results were taken on debug_defconfig which has many performance > slowing code. So, gap between base-build and w/ the test patches would be > more than the actual production build. > > Thanks, > Chintan >