From owner-freebsd-arm@freebsd.org Wed Feb 28 17:21:13 2018 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 055E9F36A3A for ; Wed, 28 Feb 2018 17:21:13 +0000 (UTC) (envelope-from the.lists@mgm51.com) Received: from oneyou.mgm51.net (oneyou.mgm51.net [IPv6:2607:f2f8:af30::100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "oneyou.mgm51.net", Issuer "RapidSSL RSA CA 2018" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 98BC483BC3 for ; Wed, 28 Feb 2018 17:21:12 +0000 (UTC) (envelope-from the.lists@mgm51.com) Received: from sentry.24cl.com (sentry.24cl.com [IPv6:2001:558:6017:94:c582:1d99:a986:7609]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "sentry.24cl.com", Issuer "Mike's Certificate Authority" (verified OK)) by oneyou.mgm51.net (Postfix) with ESMTPS id 3zs2Ql5GfdzWCYy for ; Wed, 28 Feb 2018 12:21:03 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mgm51.com; s=mgm51-02; t=1519838463; bh=TzLJ9ZsO6xh9OqOvpP6wkI034u3mkgtvU6m3Xkbe3sM=; h=Subject:To:From:Message-ID:Date; b=UQMzW8db9dh6tAimvg92jMEqIVbY0tJ8xgSVYtAaDqswESuibWawUvNXHWK1DA+vf jO16pPfJrup81ac6ayTcwbrZ73y09q1n8gwdQKwj/DczzkM2lZC9qT8+Kv9bOHf5/P C1tofZokWvV66lO00AOf7OYv+NOFzLIiKzZnYizaZTKR8nft9K4PZsEJNpPW4VLr0V xWMSCkhyP1EqwWznFX5C4twIULDLesRbgqXcZGy6XAEtKDq28KeP5JJPQhGuWnVFM0 O2pGhNUMVQ0YHEcvDYQg9xpsQzz3gJJowoduEhwCmrH8DBvF5iY6DjifVx+dcddgQi YpcakxAg6XDNQ== Received: from [IPv6:fdcf:b715:2f4d:1:a968:662f:4999:7781] (unknown [IPv6:fdcf:b715:2f4d:1:a968:662f:4999:7781]) by sentry.24cl.com (Postfix) with ESMTP id 3zs2Qk5GvHzkB4D for ; Wed, 28 Feb 2018 12:21:02 -0500 (EST) Subject: Re: Is maximum swap usage tunable? To: freebsd-arm@freebsd.org References: <20180228170311.GA26187@www.zefox.net> From: Mike Message-ID: Date: Wed, 28 Feb 2018 12:20:56 -0500 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180228170311.GA26187@www.zefox.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Feb 2018 17:21:13 -0000 On 2/28/2018 12:03 PM, bob prohaska wrote: > In watching system compilations on an RPi3 it looks as if the > system starts killing processes with "out of swap" warnings > well below 50% of full utilization (in this case, 2 GB). One > recent instance of make -j4 kernel-toolchain killed llvm-tblgen > with only 34% of the swap in use. > > Is the maximum swap usage limit adjustable in any way? I didn't > recognize anything useful in the page at > https://www.freebsd.org/cgi/man.cgi?query=sysctl(8)&sektion=&manpath=freebsd-release-ports > > It's possible the problem is really swap speed, rather than size, so I'd > like to try changing size limits if possible. The swap media claims 2-3 > MB/sec random write speed and observations with gstat seem to support the > claim, but transient stalls are hard to observe. An RPi2 with similar > hardware seems to have no problems. > > It's possible the problem is really swap speed I was running into swap speed / timeout issues. There were messages on the console to that effect. Once I put the swap space on rotating rust, that part of the compile problem disappeared. I use 1GB swap space. YMMV.