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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 E56ACC433ED for ; Tue, 11 May 2021 16:07:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8D3E61278 for ; Tue, 11 May 2021 16:07:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231916AbhEKQI2 (ORCPT ); Tue, 11 May 2021 12:08:28 -0400 Received: from mail.kernel-space.org ([195.201.34.187]:33196 "EHLO mail.kernel-space.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231126AbhEKQI2 (ORCPT ); Tue, 11 May 2021 12:08:28 -0400 X-Greylist: delayed 400 seconds by postgrey-1.27 at vger.kernel.org; Tue, 11 May 2021 12:08:27 EDT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-space.org; s=20190913; t=1620748838; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=4e3c4tHCYigd8VMYKgeRZ8N7ZU9EedN5D+Sp++U8z+0=; b=lqNHhh2g8jQLxGz2ZM5eutHuGzscK5sdlJedVtRWqfCCn6bVR+kwr9ZRw9JfIq6a/i4JbK DeO/AMV9OCyspuTj5Cm+GoQLHVsCtlSTV3lC6p9YcLyiAS1ihJZ8zsCQOyqCLPVdKFY5Bh Blg5zTGgNixld1HM4mHlPEbvoZfTniw= Received: from [192.168.0.2] (host-79-44-236-134.retail.telecomitalia.it [79.44.236.134]) by ziongate (OpenSMTPD) with ESMTPSA id 3ccdcf01 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO) for ; Tue, 11 May 2021 16:00:38 +0000 (UTC) To: linux-rt-users@vger.kernel.org From: Angelo Dureghello Subject: big rt latencies compared to non rt Message-ID: <736a53fb-d80e-3faa-1a66-d40538e0fe26@kernel-space.org> Date: Tue, 11 May 2021 18:00:01 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Hi all, i am running some RT tests on imx8qxp. Kernel is a imx (nxp) modified kernel, but with rt patch (5.4.70) that at least applies properly. Linux version 5.4.70-rt40-00120-g3e7dde1168e5-dirty I am running some histograms by cyclictest --duration=180 -t=1 -m -Sp99 \         -i2000 -h3000 -q > histogram Average is near 16uS but there are some outside values near 40000, as 000009 000000    000000    000000    000000 000010 000001    000000    000002    000000 000011 000002    000000    000000    000000 000012 000023    000006    000008    000004 000013 001565    001504    002010    001367 000014 000425    001959    000649    000700 000015 001447    001917    001129    001415 000016 034084    026118    040328    032334 000017 040537    015000    033773    041092  <----- 000018 005771    009092    007999    007512 000019 002709    023378    001790    003117 000020 000167    006238    000109    000136 000021 000135    002369    000099    000093 000022 000039    000622    000025    000041 000023 000153    000123    000026    000023 000024 000986    000178    000564    000500 000025 001872    000292    001291    001515 000026 000049    000269    000112    000081 000027 000010    000561    000011    000014 000028 000003    000296    000016    000009 000029 000005    000035    000014    000002 000030 000001    000008    000006    000000 000031 000001    000008    000006    000001 000032 000011    000002    000004    000000 Rest of the histogram is mostly 00000 values. As far as you may know, is there something i am missing for this cpu ? Thanks a lot, Regards, angelo