From owner-freebsd-hackers@freebsd.org Sun Dec 17 04:35:05 2017 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 53DA1EA13C6 for ; Sun, 17 Dec 2017 04:35:05 +0000 (UTC) (envelope-from markmi@dsl-only.net) Received: from asp.reflexion.net (outbound-mail-210-149.reflexion.net [208.70.210.149]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 00F26293C for ; Sun, 17 Dec 2017 04:35:04 +0000 (UTC) (envelope-from markmi@dsl-only.net) Received: (qmail 18905 invoked from network); 17 Dec 2017 04:34:57 -0000 Received: from unknown (HELO mail-cs-02.app.dca.reflexion.local) (10.81.19.2) by 0 (rfx-qmail) with SMTP; 17 Dec 2017 04:34:57 -0000 Received: by mail-cs-02.app.dca.reflexion.local (Reflexion email security v8.40.3) with SMTP; Sat, 16 Dec 2017 23:34:57 -0500 (EST) Received: (qmail 4223 invoked from network); 17 Dec 2017 04:34:57 -0000 Received: from unknown (HELO iron2.pdx.net) (69.64.224.71) by 0 (rfx-qmail) with (AES256-SHA encrypted) SMTP; 17 Dec 2017 04:34:57 -0000 Received: from [192.168.1.25] (c-76-115-7-162.hsd1.or.comcast.net [76.115.7.162]) by iron2.pdx.net (Postfix) with ESMTPSA id B8E14EC7B46; Sat, 16 Dec 2017 20:34:56 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: faq/troubleshoot.html#indefinite-wait-buffer has the direction of transfer wrong (head -r326888 /usr/src/) From: Mark Millard In-Reply-To: Date: Sat, 16 Dec 2017 20:34:56 -0800 Cc: FreeBSD Hackers , FreeBSD Current Content-Transfer-Encoding: quoted-printable Message-Id: <8D8CFFA3-ADE9-402F-B9A1-C311E4244FCB@dsl-only.net> References: To: Eitan Adler X-Mailer: Apple Mail (2.3273) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 17 Dec 2017 04:35:05 -0000 On 2017-Dec-16, at 8:23 PM, Eitan Adler wrote: > On 16 December 2017 at 10:47, Mark Millard = wrote: >> I got a "swap_pager: indefinite wait buffer" notice and looked >> it up. (This was on a rpi2 booted (kernel and world) from a >> USB SSD, swap partition in use instead of a swap file. It >> was building devel/cmake via poudriere-devel .) >>=20 >> = https://www.freebsd.org/doc/faq/troubleshoot.html#indefinite-wait-buffer >> reads like it is for page-out to disk: >>=20 >>=20 >> QUOTE >> 5.9. >>=20 >> What does the error swap_pager: indefinite wait buffer: mean? >>=20 >> This means that a process is trying to page memory to disk, and the = page attempt has hung trying to access the disk for more than 20 = seconds. It might be caused by bad blocks on the disk drive, disk = wiring, cables, or any other disk I/O-related hardware. If the drive = itself is bad, disk errors will appear in /var/log/messages and in the = output of dmesg. Otherwise, check the cables and connections. >> ENDQUOTE >>=20 >>=20 >> But the code containing the message is for "swread": >> (head -r326888) >=20 > If I understand correctly this is fixed by change "trying to page to" > to "trying to page from" ? In other words this happens on swap-in, > not swap-out. That is my understanding of what I reported. Side note comparing with rpi2 (armv7, cortex-A7): A rpi3 (aarch64, cortex-A53) got a couple of the messages during a build of the same port: devel/cmake . In this case it is emmc attached to the microsd-card slot via an adapter, instead of a USB SSD stick. =3D=3D=3D Mark Millard markmi at dsl-only.net