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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 065C2C433E0 for ; Thu, 11 Mar 2021 15:06:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEB4B64FF7 for ; Thu, 11 Mar 2021 15:06:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234003AbhCKPGK (ORCPT ); Thu, 11 Mar 2021 10:06:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233921AbhCKPFt (ORCPT ); Thu, 11 Mar 2021 10:05:49 -0500 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A1C0C061574 for ; Thu, 11 Mar 2021 07:05:48 -0800 (PST) Received: by mail-lf1-x12e.google.com with SMTP id v2so27261787lft.9 for ; Thu, 11 Mar 2021 07:05:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=austral-dynamics-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :content-transfer-encoding; bh=PO/dIvRkAgIddp8p+DMn/BKAAKJFzJs05581/49xIJc=; b=pU0GaasMD3QQDyTf82ObAzRWZmPtEu/+yD7XGxoQd6HgGV1WS9BNYDs7K4gzQFoIO7 YO5XlJHPymhpytlQgeMFHYVs9lDo7dUNeSN9EBi0RAOyLBb69DE8hOa6CTZj0n1aaHnS V17OvTDLJccvPnD06NXe/Q6wjws60cmXP5y5IiYR/TcJCBSTgq8RsPDinBEbHdQ5Hpg1 8zDKi2ajOpyFIM68Lsi7tQb4Ttfa/dqJlyoRQTnh3G8BXlPXjLJvx9N2JcyMJxNCQeVU fIxmfUqMOfXn7WHWVZPgmhHUBX8ywnB0H93JtTtOp5ILtw95W04B7OB0eSY5e7Mn3JIz 4DRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:content-transfer-encoding; bh=PO/dIvRkAgIddp8p+DMn/BKAAKJFzJs05581/49xIJc=; b=UeVopOnFtsb5m3lNuVsNM+EaKczHMhS+KKC+EgxmoGgO2BVjMDc+Ed3NA9+WM7Rw84 XxJcGaLI2iAIvX0oDdUzVuSsZ+zyWY45H8jTivY2mLUw+r3yU/o5Z9j0X86zjlw5JJwQ aOYWPcBzHuSsStPia5WDKGgw+J/7213dmMfK2++BfmPp4lTlkSu1X1VMpZgwThmrk/nM pJufezxloP/FrtyTkKll66BHdwRBH91xcf5LpNsgzbRMH4GzPJuxUUNnWl6zIpwiQupO 273X7dJPDZPTDJod/upDVEfdKkiDHRvxFB6Ayn10HvCwv2PBcjmoetvK9OsB5RCtIx/l xjhA== X-Gm-Message-State: AOAM532TFmLMNm+fApt31gndKNN3UcTeapVNuiog56xNx2UMLDxXDQhv M1k7DZMK7DPligVTeoBQunxLfz/q1vtzYPeUxPQitzlXgw8= X-Google-Smtp-Source: ABdhPJwAcgpnPd62SHVZGNs6EK1p3N9Z2kp1Ygt26M1qRClv79XqP8fI59t1uG93C76uS+V1EsxSXyJlheCMkenLPe8= X-Received: by 2002:a19:9116:: with SMTP id t22mr2645648lfd.93.1615475147135; Thu, 11 Mar 2021 07:05:47 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Michel Macena Oliveira Date: Thu, 11 Mar 2021 12:03:54 -0300 Message-ID: Subject: Re: PREEMPT_RT benchmark To: "Ahmed S. Darwish" , linux-rt-users@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Hi Ahmed, thanks for the answer! Do you know if it would be valid for GTK interface applications? Michel Em qui., 11 de mar. de 2021 =C3=A0s 09:58, Ahmed S. Darwish escreveu: > > On Wed, Mar 10, 2021 at 05:07:47PM -0300, Michel Macena Oliveira wrote: > > > > I'm currently developing a time benchmark application where I want > > to measure a real time thread latency. My application is based on > > Cyclictest from > > the rt-tests suit. > ... > > > > I programmed in such way that it would be equivalent to Cyclict test > > > ... > > > > At least that's what I expected, but my latencies are much bigger than > > Cyclictest ones. > > > > I don't know the nature of the "time benchmark" application you are > writing. > > Just a small hint that if you're doing any heavy OpenGL graphics within > that application, the latency can shoot up significantly. On some of our > Intel boxes, this can lead to an increase of 100-200 microseconds. > > That's because since Intel Gen9+ GPUs, Intel shares the Last-Level Cache > (and thus also memory bandwidth) between the GPU and the CPU. This > benefits graphical applications, but hurts predicatbility significantly. > > Good luck, > > -- > Ahmed S. Darwish > Linutronix GmbH