Date: Fri, 26 Mar 2021 10:55:47 +0100 From: "Nils B." <boulder@renzel.net> To: Andriy Gapon <avg@FreeBSD.org>, freebsd-current@freebsd.org, freebsd@grem.de, monochrome@twcny.rr.com Subject: Re: freebsd 13 ryzen micro stutter Message-ID: <53edce3f-6386-a91a-f96b-b804ad0c5f21@renzel.net> In-Reply-To: <4efc1460-4460-6876-5a93-ea80c5866fa2@FreeBSD.org> References: <d793c8b7-e0e2-e0d9-3ecd-923134d15bf3@twcny.rr.com> <20210323101146.18c9a969@bsd64.grem.de> <ED533759-D326-45D5-8AE2-51CB10763A1E@unrelenting.technology> <711646dd-1ff7-32e9-f3da-0add1565519a@renzel.net> <4efc1460-4460-6876-5a93-ea80c5866fa2@FreeBSD.org>
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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
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