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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 F402DC7618F for ; Wed, 17 Jul 2019 00:45:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD8742182B for ; Wed, 17 Jul 2019 00:45:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sfM/F4Jk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729263AbfGQApI (ORCPT ); Tue, 16 Jul 2019 20:45:08 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:35798 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726344AbfGQApH (ORCPT ); Tue, 16 Jul 2019 20:45:07 -0400 Received: by mail-wr1-f65.google.com with SMTP id y4so22835120wrm.2 for ; Tue, 16 Jul 2019 17:45:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=n0uCJBo++JsrvADGMMRn+NTcY07/65qMGSkIRUa45eQ=; b=sfM/F4JkOtYStXJ4492l4nMxSNysB0mhvgdzzCW/0Gjtt9Ysipn7MrMiBqzd6c4ofg cGNZcRAGQ9I4P+oe8TJdkbScnVxK29w0pJd5N6XtSjN5jlirLvgmMmRdGcxki4tCgU+J yAeTBYD9WuURNXlHVda2bO+9CXkFYTru2tttTEQ/K4xktUOq7kndNgK6KRFpAxLE7+2U 4xXAm6o3Fz0xIf+wRdBloSJB8X1GbzNOYYpoACzBrp3vhOlThnksd48HRZzWaysyTlB2 SNClJuKM7WqA2wU/Pxx/jUZAs7BKWBWOTVBiTXl1MtYZ81j3ep55OI/Bl+W9w2lV3tlo PSSA== 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:cc; bh=n0uCJBo++JsrvADGMMRn+NTcY07/65qMGSkIRUa45eQ=; b=ttWio3NjTdN7MQibg1kqLXHw+XvrVV/dzrpmtQ6U/k6X6KDkkYNdZirhIWMc0wCboM HXha4D6jEjV1U7r/lbBpjOJ1VKdlvw28LLjefXAVNs9N/FsBNBQBNkIYFFzIaOukTfNN eRfCTiX5U+0htD58176pOmxoPC2dNf9IR+4dLUZ0A8a7A4gBDmZW3SdZOkCLxwl8MaA/ XIX/OcJauk9ZqwCDt5J5Ox/gkazrka60nhpn+SnIwPfR+C1ynHjlHJPRZ3O9tCCpNtlP rBN62eR8Q/vAWXJw014ElBbXB2TxOKOtOO9My+ES2b0MTOzBUQVWzQDEQ1sYLiRCDVJn pNZQ== X-Gm-Message-State: APjAAAVcrkeQZiOB4aiOoi0ZlD/NTBROjSQorPfD5v1iLjBGS07IGDvJ 9EYnpuIuXyxv8s9OXqkIjoLqb9iJG4zj4gQT920= X-Google-Smtp-Source: APXvYqw0JhD7XByl/d7/fBeM4DgeJZkHwdGbEMbV+kMrKZEsgATdQ7VSxvBPEhnF3vxC2XGUWyKedVGZE2A63wk0dCo= X-Received: by 2002:a5d:51c7:: with SMTP id n7mr11410083wrv.326.1563324305379; Tue, 16 Jul 2019 17:45:05 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Paul Thomas Date: Tue, 16 Jul 2019 20:44:53 -0400 Message-ID: Subject: Re: poor cyclictest results with 5.0 series rt for arm64 To: Thomas Gleixner Cc: linux-rt-users , dunc.mcphie@gmail.com, Anders Roxell Content-Type: text/plain; charset="UTF-8" Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Tue, Jul 16, 2019 at 7:14 PM Thomas Gleixner wrote: > > On Tue, 16 Jul 2019, Paul Thomas wrote: > > > > > We do have trace data for a instance where cyclictest hit 5000 uS, but > > > > the file is large 11MB, and I wasn't sure if I should directly attach > > > > it to the email. What is the best way to post or send this? > > > > > > Can you upload the trace to some place? If you don't have storage, just use > > > bugzilla.kernel.org and open a bug, attach it and post a reference. > > > > Hi Thomas, > > > > I've put the last 60k line of the trace on the bug report here: > > https://bugzilla.kernel.org/show_bug.cgi?id=204189 > > > > Just looking at the timestamp time of cyclicte-2778 I can see the last > > two finish_task_switch calls are seperated by 5801 uS. Is just before > > that the correct place to be looking? > > Right. If I'm reading it correctly, I think I know what's wrong. Can you > please revert: > > 80e7f3b05365 ("arch/arm64: Add lazy preempt support") > > Either that patch is broken or it got broken on forward porting it from > 4.19. Need to look with brain awake tomorrow. Yes! this looks like it fixes it. The hash I see is slightly different: b7f42e8fb48cbe38e4c2d0cab48309aadfa6d032 But the name was the same "arch/arm64: Add lazy preempt support" I did a quick run with 5.0.19-rt11 with these results: root@xu5:/opt/rt-tests# ./cyclictest -S -m -n -p 99 -i 200 -h 400 -D 900 # /dev/cpu_dma_latency set to 0us policy: fifo: loadavg: 0.64 0.74 0.60 1/131 1931 T: 0 ( 1913) P:99 I:200 C:4499993 Min: 5 Act: 8 Avg: 7 Max: 20 T: 1 ( 1914) P:99 I:200 C:4499899 Min: 5 Act: 8 Avg: 7 Max: 16 T: 2 ( 1915) P:99 I:200 C:4499799 Min: 5 Act: 8 Avg: 7 Max: 17 T: 3 ( 1916) P:99 I:200 C:4499704 Min: 5 Act: 8 Avg: 7 Max: 16 We'll do some more testing tomorrow. -Paul