From nobody Mon Nov 3 11:57:01 2025 X-Original-To: fs@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 4d0VSF2m6pz6Fbyb for ; Mon, 03 Nov 2025 11:57:01 +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 "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4d0VSF20qvz44gw for ; Mon, 03 Nov 2025 11:57:01 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1762171021; 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=hSLGYlhCX502x3ePd0ZLYAh3T4Yhpqg0qYXo3hQ3tXg=; b=GMtoGOdIqiOsTlGUEHNFqxmPsk4PdzNGdvRi8D1lvl6NYra5u6eCQ0bH5E9PU3lRe7pXUC MFCFlccGTCzMzGOQntcfxmWur7F+MPtCWQUU4oUv17CJpp8KfGRCHlfiCR5HvUchTNLm+w KgpwtPSsxCZKwVeMAo2TyuQUYdyYbnokQgbHLuCbjVDB+uFVtkVOT2MBowc/GTq+gx8vwu EDFK0yf8d2tAS+kXRAHg2/XTcfmunFXuN8eaIkLURdchNqeUb8s7Cr5aEcJKdQGfyzcGs+ ORBiUzlPyCfvKopjcxZ811uLssXtGuWZUYeutGGnfjrWY8Y72k6W5pRxYiWKMg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1762171021; 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=hSLGYlhCX502x3ePd0ZLYAh3T4Yhpqg0qYXo3hQ3tXg=; b=onD7XbF4DL8Ss/EBJR8uVafV2oPvLtzl7w/Ro0s0y7ylQiRuB39MaJ9swJ8at3GhX4HqCy iO2Pbq9R7G2tuYkcYEO/7TTeTIQeBc5z4EOwO9n1lMeShYKWA9pp0ieEm5Ua6oqlu4dXfd MczOxtveh7KjejA5eSFOySvM3k+bMTLLFe0MUSVv690h/FsWtWY4Sp+0cx8pRI1sx4LIen V41Ig+REuPx70Hsud0G6/ej2Gu8MetmyC1xSQzEkjJFKGUiiH47oFJS7yPy626b5D7Qxi0 DQXErV5TjrtzxfFNRccsAm1/Sm1L22Ot05uiTW20Cmqgk9yYhZtNk9zRRFZcsA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1762171021; a=rsa-sha256; cv=none; b=t09b0fd8paM5ocK9Oumw60ETxJABgc3iTzPBlRuA4nCYk1BU4jfE6nGWSkexqkM48U66BZ 7XIfMcFucBaG2EUWcMeyA9N6f4L1Pq1jmqVT3VQrzGu4qbfOGoq9kzwTcV75OMkN73pCOg g9VeMBQfT5HK2S+dEoBGWyVHstTTXFXueI8gTl16PAiZw4eLx03Y4FYQjKQOOG4G5SFFar 5ONM5paeTlZC09PmdZLWrtzyuE6WylYwOmOPD6O5Bncz9z1xwILUnE9p7cMi3zV7xIrd/e 2yrI0XWUGFW1lZHTu2OiLu8iol//gVCR87SBAZ83VYty88JRNDfFA5EIt7G7jg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none 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 4d0VSF1NkSz18qk for ; Mon, 03 Nov 2025 11:57:01 +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 5A3Bv1wJ017564 for ; Mon, 3 Nov 2025 11:57:01 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 5A3Bv1Ar017563 for fs@FreeBSD.org; Mon, 3 Nov 2025 11:57:01 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: fs@FreeBSD.org Subject: [Bug 290207] [ZFS] lowering "vfs.zfs.arc.max" to a low value causes kernel threads of "arc_evict" to use 91% CPU and disks to wait. System gets unresponsive... Date: Mon, 03 Nov 2025 11:57:01 +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: 15.0-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: nbe@vkf-renzel.de X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: fs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Filesystems List-Archive: https://lists.freebsd.org/archives/freebsd-fs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-fs@FreeBSD.org MIME-Version: 1.0 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D290207 --- Comment #35 from Nils Beyer --- well, "arc_available_memory" is defined as n =3D PAGESIZE * ((int64_t)freemem - zfs_arc_free_target); or [if !defined(UMA_MD_SMALL_ALLOC) && !defined(UMA_USE_DMAP)] n =3D uma_avail() - (long)(uma_limit() / 4); So, in my eyes, for "arc_available_memory" any setting for "vfs.zfs.arc.max= " is ignored and therefore "arc_lowmem" not triggered until the real available f= ree memory goes down - for instance by using a large TMPFS... --=20 You are receiving this mail because: You are the assignee for the bug.=