From owner-freebsd-questions@freebsd.org Thu Feb 27 11:30:24 2020 Return-Path: Delivered-To: freebsd-questions@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 45C6825DBE6 for ; Thu, 27 Feb 2020 11:30:24 +0000 (UTC) (envelope-from luciano@vespaperitivo.it) Received: from baobab.bilink.net (baobab.bilink.net [212.45.144.44]) by mx1.freebsd.org (Postfix) with ESMTP id 48Sr7b6bMKz47qh for ; Thu, 27 Feb 2020 11:30:19 +0000 (UTC) (envelope-from luciano@vespaperitivo.it) Received: from baobab.bilink.net (localhost [127.0.0.1]) by baobab.bilink.it (Postfix) with ESMTP id 48Sr7Y00H1z1ftWd for ; Thu, 27 Feb 2020 12:30:17 +0100 (CET) Received: from hermes.mcs.it (hermes.mcs.it [192.168.132.21]) by baobab.bilink.it (Postfix) with ESMTP id 48Sr7X6M0Lz1ftWZ for ; Thu, 27 Feb 2020 12:30:16 +0100 (CET) Received: from mordeus (unknown [192.168.45.6]) by hermes.mcs.it (Postfix) with ESMTP id B6C524D5CC0 for ; Thu, 27 Feb 2020 12:30:16 +0100 (CET) Date: Thu, 27 Feb 2020 12:30:06 +0100 From: Luciano Mannucci To: freebsd-questions@freebsd.org Subject: swap_pager: indefinite wait buffer X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; amd64-portbld-freebsd12.0) X-Face: 4qPv4GNcD; h<7Q/sK>+GqF4=CR@KmnPkSmwd+#%\F`4yjKO3"C]p'z=(oWRnsYBQGM\5g:4skqQY0NnV'dM:Mm:^/_+I@a"; [-s=ogufdF"9ggQ'=y MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <48Sr7X6M0Lz1ftWZ@baobab.bilink.it> X-Virus-Scanned: PippoLillo, ClamAV using ClamSMTP X-Rspamd-Queue-Id: 48Sr7b6bMKz47qh X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of luciano@vespaperitivo.it designates 212.45.144.44 as permitted sender) smtp.mailfrom=luciano@vespaperitivo.it X-Spamd-Result: default: False [-5.01 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:212.45.144.0/24]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-questions@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; RCVD_COUNT_THREE(0.00)[4]; DMARC_NA(0.00)[vespaperitivo.it]; RCVD_IN_DNSWL_NONE(0.00)[44.144.45.212.list.dnswl.org : 127.0.10.0]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:8816, ipnet:212.45.128.0/19, country:IT]; IP_SCORE(-2.81)[ip: (-8.07), ipnet: 212.45.128.0/19(-4.03), asn: 8816(-1.96), country: IT(0.03)] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Feb 2020 11:30:24 -0000 Hello everybody! Since my last upgrade (to 11.3-RELASE-p6) I've noticed some messages in the daily security report of one of my PPC 64 virtual servers, that runs under KVM/Qemu, which says: Feb 26 20:17:53 Saguaro kernel: swap_pager: indefinite wait buffer: bufobj: 0, blkno: 1698063, size: 20480 (numbers vary, of course) It happens only under heavy IO. I can reproduce this by launching a backup (I use bacula). I moved the swap to cooked files, just in case it was a hardware problem, which gave me only more messages of this kind. I know that the handbook recommends to check hardware & cables, but being on a virtual machine makes it a bit nonsensical. The machine does'nt lack ram, it has 8 CPUs and 8 Gigabytes of ram. This is vmstat: procs memory page disks faults cpu r b w avm fre flt re pi po fr sr md99 md98 in sy cs us sy id 0 0 0 14G 1.2G 687 8 1 0 747 951 0 0 0 1622 704 3 1 95 and swapinfo says: Device 1K-blocks Used Avail Capacity /dev/md99 2097152 420564 1676588 20% /dev/md98 2097152 419352 1677800 20% Total 4194304 839916 3354388 20% Is there something I should check? Any kernel variables tunable via sysctl? Thanks for any answer, Luciano. -- /"\ /Via A. Salaino, 7 - 20144 Milano (Italy) \ / ASCII RIBBON CAMPAIGN / PHONE : +39 2 485781 FAX: +39 2 48578250 X AGAINST HTML MAIL / E-MAIL: posthamster@sublink.sublink.ORG / \ AND POSTINGS / WWW: http://www.lesassaie.IT/