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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 391D2C2D0CF for ; Tue, 24 Dec 2019 14:03:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A092206D3 for ; Tue, 24 Dec 2019 14:03:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726262AbfLXODp (ORCPT ); Tue, 24 Dec 2019 09:03:45 -0500 Received: from foss.arm.com ([217.140.110.172]:52286 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726124AbfLXODo (ORCPT ); Tue, 24 Dec 2019 09:03:44 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 489DB1FB; Tue, 24 Dec 2019 06:03:44 -0800 (PST) Received: from [10.0.2.15] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0488F3F534; Tue, 24 Dec 2019 06:03:42 -0800 (PST) To: linux-kernel , LAK , tee-dev@lists.linaro.org, netdev@vger.kernel.org From: Valentin Schneider Subject: 5.5-rc1 regression with BNXT firmware driver Cc: vikas.gupta@broadcom.com, jakub.kicinski@netronome.com, sheetal.tigadoli@broadcom.com, davem@davemloft.net, Vincent Guittot Message-ID: <86d05f68-e644-8b05-3154-4658813e986e@arm.com> Date: Tue, 24 Dec 2019 14:03:35 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I've been hunting down some hackbench regression between 5.4-rc8 and 5.5-rc1 on my Juno r0, one of the offenders seems to be: 246880958ac9 ("firmware: broadcom: add OP-TEE based BNXT f/w manager") This is tested on a kernel built with defconfig (TEE_BNXT_FW gets selected) and with: echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor echo performance > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor ./perf stat --null --sync --repeat 200 ./hackbench The regression is easily reproducible on my end, this is 3 runs of the above comparing the patch and its parent: -PATCH: 0.71062 +- 0.00150 seconds time elapsed ( +- 0.21% ) 0.71121 +- 0.00181 seconds time elapsed ( +- 0.25% ) 0.71277 +- 0.00181 seconds time elapsed ( +- 0.25% ) +PATCH: 0.72556 +- 0.00174 seconds time elapsed ( +- 0.24% ) 0.72695 +- 0.00192 seconds time elapsed ( +- 0.26% ) 0.72559 +- 0.00178 seconds time elapsed ( +- 0.25% ) AIUI Vincent found something different while hunting down a similar regression: df323337e507 ("apparmor: Use a memory pool instead per-CPU caches") but it seems this one is another cause. Seeing as this involves security stuff the overhead may be acceptable, nevertheless now that I have some reproducer I figured I'd send this out. Cheers, Valentin