From nobody Thu Dec 07 19:06:03 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 4SmNz02Rhzz53SKS for ; Thu, 7 Dec 2023 19:06:04 +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 4SmNz01Ds3z4k4B for ; Thu, 7 Dec 2023 19:06:04 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1701975964; a=rsa-sha256; cv=none; b=T0cSrfPkXdHUKUEnmoUlyAyZbjlT3VLMNIGtrUWqiwheLZz5hG0UEpM9hwHud5xMMiDQ52 fzOvqjiGCt+QSJMg+ewYwd/RTh4NpodFydhGSAWzrYyCsalgyq1cl6wlph+D6P30nV1sSr lsG5a/Bi1Z1s3rmJg56BQNoKd0P0Kq7JrwpHpwgOXzgi1vB+MSzZK4rsFw5wC0NvQ6bMT4 GCOYL93Rd6xfUNTMA8DLWm/rUCjymbsNut1imVJEZnvBTLfkJ4bkDOL7SAkHhfv10GC7Jj dtTnx7gAFa/a2IRWV1dze9D48w/WYUZu3OnNUKHg2L9bBOi3YoumYroreN4dzQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1701975964; 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=sQajclsn6ANkrRxQDsy131/e+SsSddZKEI7pkYgNSBw=; b=ZgeUtEXKmV+Zr/rOhNP8h/G/118vmc21+1N2dKJTUD+nbyZuC6XfBG/cuQKcR2fB/IaqOE 4zB9B7ZaX6FTZKX6g2Ok5fYbtZ/6ZuYITYtlBZOCjQFxndG2Eq8YZ2z0NFfiDl1r0fPmvd o+zQ3efRHwjCLZBtOnm+kwzbOJ3gqgGBeennbIzoyVSTtkI+tvi3ZB1SjcosyFEm0egegQ Yn6CAKXi6ZvOC2gmxxbBNRsepkMmr2H4aGwE7nuhOsoKdtzxib1c/evEPQRzsGVe5Q4TqJ PibyFeRKHo+qujI03RJgW8k8yyk6NUAwFosaFkg5FfchzhCjHYKxhkzmOEwqxw== 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 4SmNz00Byyzptb for ; Thu, 7 Dec 2023 19:06:04 +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 3B7J63gR024792 for ; Thu, 7 Dec 2023 19:06:03 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 3B7J6376024791 for bugs@FreeBSD.org; Thu, 7 Dec 2023 19:06:03 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 275594] High CPU usage by arc_prune; analysis and fix Date: Thu, 07 Dec 2023 19:06:03 +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: 14.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: seigo.tanimura@gmail.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: 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=3D275594 --- Comment #2 from Seigo Tanimura --- > Why did you change this parameter? In my test case, the ARC pruning process has the risk of hitting many non-Z= FS vnodes. vfs.vnode.vnlru.max_free_per_call has hence been increased in the = hope to reach the ZFS vnodes with the better chance within a single iteration. > USE_TMPFS=3D"wrkdir data localbase" The directories under the really heavy load are covered by tmpfs(5). > What happens if you leave it at the default value? I started "poudriere bulk" about an hour ago with: - vfs.vnode.vnlru.max_free_per_call: 10000 (out-of-box) - vfs.zfs.arc.prune_interval: 0 (cancel the ARC pruning interval) The rest of the setup is the same as in the description. After about 50 minutes from the start, arc_prune started to hog the CPU up = to 90 - 100%. The free_retry and free_giveup counters are increasing in the s= ame pace as free_call. I will continue this build until the end, but with no hope for the recovery= of arc_prune. --=20 You are receiving this mail because: You are the assignee for the bug.=