From owner-freebsd-current@freebsd.org Fri Mar 26 09:55:50 2021 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id E81285B9B8F for ; Fri, 26 Mar 2021 09:55:50 +0000 (UTC) (envelope-from boulder@renzel.net) Received: from mx1.renzel.net (mx1.renzel.net [195.243.213.130]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "*.renzel.net", Issuer "DigiCert SHA2 Secure Server CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F6HRB0bjYz4Skx; Fri, 26 Mar 2021 09:55:49 +0000 (UTC) (envelope-from boulder@renzel.net) X-Virus-Scanned: GDATA Antivirus at gdata-milter.renzel.de.isb X-Spam-Score: 0 X-Spam-Level: X-Spam-Status: No, score=-997.8 required=9.0 tests=ALL_TRUSTED=-1000, BAYES_50=1,NICE_REPLY_A=-0.001,NORMAL_HTTP_TO_IP=0.001, NUMERIC_HTTP_ADDR=1.242,WEIRD_PORT=0.001 autolearn=no autolearn_force=no version=3.4.2 Received: from dublin.vkf.isb.de.renzel.net (unknown [62.159.136.5]) by mx1.renzel.net (smtpd) with ESMTP id 3FD64D98C5; Fri, 26 Mar 2021 10:55:47 +0100 (CET) Received: from asbach.renzel.net (unknown [172.18.96.1]) by dublin.vkf.isb.de.renzel.net (Postfix) with ESMTPA id 223D2866DE; Fri, 26 Mar 2021 10:55:47 +0100 (CET) From: "Nils B." Subject: Re: freebsd 13 ryzen micro stutter To: Andriy Gapon , freebsd-current@freebsd.org, freebsd@grem.de, monochrome@twcny.rr.com References: <20210323101146.18c9a969@bsd64.grem.de> <711646dd-1ff7-32e9-f3da-0add1565519a@renzel.net> <4efc1460-4460-6876-5a93-ea80c5866fa2@FreeBSD.org> Message-ID: <53edce3f-6386-a91a-f96b-b804ad0c5f21@renzel.net> Date: Fri, 26 Mar 2021 10:55:47 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <4efc1460-4460-6876-5a93-ea80c5866fa2@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on nijmegen.renzel.net X-Rspamd-Queue-Id: 4F6HRB0bjYz4Skx X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of boulder@renzel.net designates 195.243.213.130 as permitted sender) smtp.mailfrom=boulder@renzel.net X-Spamd-Result: default: False [-3.50 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[renzel.net]; NEURAL_HAM_LONG(-1.00)[-1.000]; RWL_MAILSPIKE_GOOD(0.00)[195.243.213.130:from]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_MED(-0.20)[195.243.213.130:from]; NEURAL_HAM_SHORT(-1.00)[-1.000]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:3320, ipnet:195.243.0.0/16, country:DE]; RCVD_TLS_LAST(0.00)[]; MAILMAN_DEST(0.00)[freebsd-current] X-Mailman-Approved-At: Fri, 26 Mar 2021 16:17:21 +0000 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Mar 2021 09:55:51 -0000 On 25.03.21 16:31, Andriy Gapon wrote: > [...] > There are some tools in tools/sched/ directory. > schedgraph.py can be used for visual inspection of scheduling traces collected > using KTR. The file has instructions on how to collect them. > Alternatively, schedgraph.d can be used to collect such traces. > If anyone affected can gather a short sample that captures the problem, then > there might be someone who would be willing to look at them. what should I tell? I've set "kern.sched.steal_thresh: 0 -> 2" and reliably got that micro-suttering back while watching YouTube videos (tearing test i.e.). Then I loaded kernel modules "dtrace.ko" and "dtraceall.ko" and ran ./schedgraph.d > /tmp/sched.out The micro-stuttering immediately went away while above DTrace-script was running. So it seems that the light load of the running DTrace-script was enough to eliminate any micro-stutterings. I've uploaded resulting .ktr- and .out-files (for both steal_thresh=2/0) here: kern.sched.steal_thresh=2 ------------------------- http://156.67.189.93:9080/sched.steal2.txz kern.sched.steal_thresh=0 ------------------------- http://156.67.189.93:9080/sched.steal0.txz Haven't tried your mentioned first KTR-variant yet... Thanks and BR, Nils