From owner-freebsd-hackers@freebsd.org Tue Jul 7 17:30:36 2020 Return-Path: Delivered-To: freebsd-hackers@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 820FB367AF6 for ; Tue, 7 Jul 2020 17:30:36 +0000 (UTC) (envelope-from gbe@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (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 (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4B1Twr2zdzz3dW6; Tue, 7 Jul 2020 17:30:36 +0000 (UTC) (envelope-from gbe@freebsd.org) Received: from localhost (p548612f6.dip0.t-ipconnect.de [84.134.18.246]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) (Authenticated sender: gbe) by smtp.freebsd.org (Postfix) with ESMTPSA id 095042EF3E; Tue, 7 Jul 2020 17:30:35 +0000 (UTC) (envelope-from gbe@freebsd.org) Date: Tue, 7 Jul 2020 19:30:34 +0200 From: Gordon Bergling To: Andriy Gapon Cc: Allan Jude , freebsd-hackers@freebsd.org Subject: Re: Constant load of 1 on a recent 12-STABLE Message-ID: <20200707173034.GA92732@lion.0xfce3.net> References: <20200603101607.GA80381@lion.0xfce3.net> <20200603202929.GA65032@lion.0xfce3.net> <8b1498ea-e343-506e-79c7-c25b594808f0@freebsd.org> <20200604123720.GA63595@lion.0xfce3.net> <20200623072332.GA54653@lion.0xfce3.net> <0a10a722-3eec-456b-d771-97a49af89ad1@FreeBSD.org> <20200705080605.GA53520@lion.0xfce3.net> <4e38b243-6596-2f88-2df8-2a954ba70a47@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4e38b243-6596-2f88-2df8-2a954ba70a47@FreeBSD.org> X-Url: X-Operating-System: FreeBSD 12.1-STABLE amd64 X-Host-Uptime: 7:03PM up 4 days, 7:51, 5 users, load averages: 1.04, 1.10, 1.13 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Jul 2020 17:30:36 -0000 Hi Andriy, On Sun, Jul 05, 2020 at 02:39:38PM +0300, Andriy Gapon wrote: > On 05/07/2020 11:06, Gordon Bergling wrote: > > I didn't use the ZFS multi-modifier protection feature and didn't have the 'multihost' > > propery set on any of my 3 ZFS pools. Thanks for identifing the particular change. I > > have tried OpenZFS from ports, which seems to improve the situation, but I went back > > to the base version since only the zroot pool was found and the two others pools > > weren't detected. > > You can try to use dtrace or hwpmc or some such to see what those mmp threads > are doing. I filed a PR [1] for the issue. I already worked my way through the dtrace one-liners on the wiki, but I wasn't that successful on getting an insight into what ever the mmp threads were doing. I'll try to attend the upcoming Bug Squash Hackathon and work on that issue. --Gordon [1] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=247829