From nobody Wed Nov 15 18:00:23 2023 X-Original-To: bugs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4SVrYM5ljlz50Yl8 for ; Wed, 15 Nov 2023 18:00:23 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (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 "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4SVrYM4886z4Kl7 for ; Wed, 15 Nov 2023 18:00:23 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1700071223; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2Hlu2i1/6WLsuCQ5AWWHSx3+/hlrqbqEXOBOQ0k23mA=; b=ksDRU+J+9nvbHJlGEXxz2AJjDlLCqPnNxv0HTwAzXuTYcQkHO65XWLsR24IjPFjzoqqZkC yOgoWhY1k+DhWwk6qTOWbFQ1ktib8baBbXZOXnSs9+somts7aoKAffuNwjI+RX4t9y/E4/ ceXrZTRW8GSlCKjVpcLzYk8KL5P7ed3en5IaGHIArJ2zY4iiNlZrASK7FNyRc7XUPENuyy sfqn3r6oIaNwBULNjIGyBdzCfxVgQ/sHXMCQVuCAaPH5Jnr11ce7yToldtB1dUSOADnBbX DKkCuuLuEA5gnU+zLhXeI/BhXGgaEJ+LsDVXXjvIb1WroUZgQ7aZlLkgkuoC3w== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1700071223; a=rsa-sha256; cv=none; b=dPrxn7e9JP9cw0N0hL2Mzq5o6iJtyO3ksYBOKQ904rqFMPeXH34UEqt7vWDg3CEy/oav5P CRiHO6o9svd+mWEDWawdk4XEulsemprpfxf3RCrS6C3+zWHxeAXygYDh48K5oSNGuI+j6V Cb4/Cbtyg5qNFeLe9Vn7bOZkYCxl33e8LMUI/w05FfkEiWEpEGKb5JvmM5+vd1Re7v0odE s+4GhOBSKCh9ko2jWVuDZLNsr7J1C/O/x2r7YIyGhKXPPcnMFeycntfmRI8zsT6lEHq416 7Uqn7jao8GRHCC2fadolvt+Oqi/WoSyx8jmPRyfZhMqx8n1D/zTu+lZ5fMzrCg== Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (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 did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4SVrYM3CwXzBZj for ; Wed, 15 Nov 2023 18:00:23 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 3AFI0Nbs043325 for ; Wed, 15 Nov 2023 18:00:23 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 3AFI0NYU043324 for bugs@FreeBSD.org; Wed, 15 Nov 2023 18:00:23 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 275063] kernel using 100% CPU in arc_prune Date: Wed, 15 Nov 2023 18:00:23 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: Unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: d8zNeCFG@aon.at X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: mfc-stable13? X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Bug reports List-Archive: https://lists.freebsd.org/archives/freebsd-bugs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-bugs@freebsd.org MIME-Version: 1.0 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D275063 --- Comment #3 from Martin Birgmeier --- Just for information: This condition is triggered reliably as follows: - Create a sparse/compressed zvol: zfs create -o compress=3Don -s -V 20g hal.1/vdisks/903 - In a VM, slice & partition it in the old-fashioned way for carrying UFS filesystems: ada0s4a, ada0s4d (for / and /usr) - With the VM not running and from the host side, mount one of these filesystems - Run dd if=3D/dev/zero of=3D/ until filesystem full; = this is done to remove unallocated blocks because the sparse/compressed zvol discar= ds blocks of zeros - The dd operation reliably triggers the arc_prune issue. The draining of taskq_zone (see PR 274698) is so slow that it would take ma= ny hours (on an otherwise completely idle system): [0]# vmstat -z | egrep '^ITEM|taskq' ; sleep 60 ; vmstat -z | egrep '^ITEM|taskq' ITEM SIZE LIMIT USED FREE REQ FAILSLEEP XDOMAIN taskq_zone: 192, 0, 2221547, 28456, 2980856, 0, 0, = 0 ITEM SIZE LIMIT USED FREE REQ FAILSLEEP XDOMAIN taskq_zone: 192, 0, 2218760, 31243, 2980868, 0, 0, = 0 [0]#=20 A linear extrapolation results in about 13.3 hours. -- Martin --=20 You are receiving this mail because: You are the assignee for the bug.=