From owner-freebsd-hackers@freebsd.org Mon Nov 19 15:51:22 2018 Return-Path: Delivered-To: freebsd-hackers@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 8B0AF11078D0 for ; Mon, 19 Nov 2018 15:51:22 +0000 (UTC) (envelope-from freebsd-rwg@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A0EA37B95B for ; Mon, 19 Nov 2018 15:51:21 +0000 (UTC) (envelope-from freebsd-rwg@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (localhost [127.0.0.1]) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3) with ESMTP id wAJFpHO6062221; Mon, 19 Nov 2018 07:51:17 -0800 (PST) (envelope-from freebsd-rwg@pdx.rh.CN85.dnsmgr.net) Received: (from freebsd-rwg@localhost) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3/Submit) id wAJFpHn3062220; Mon, 19 Nov 2018 07:51:17 -0800 (PST) (envelope-from freebsd-rwg) From: "Rodney W. Grimes" Message-Id: <201811191551.wAJFpHn3062220@pdx.rh.CN85.dnsmgr.net> Subject: Re: 13-CURRENT: several GB swap being used despite plenty of free RAM In-Reply-To: <201f06e9-54b8-32f5-e4ef-be694d511d93@multiplay.co.uk> To: Steven Hartland Date: Mon, 19 Nov 2018 07:51:17 -0800 (PST) CC: freebsd-hackers@freebsd.org X-Mailer: ELM [version 2.4ME+ PL121h (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Rspamd-Queue-Id: A0EA37B95B X-Spamd-Result: default: False [0.78 / 15.00]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[dnsmgr.net]; AUTH_NA(1.00)[]; NEURAL_SPAM_MEDIUM(0.22)[0.216,0]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; MX_GOOD(-0.01)[cached: pdx.rh.CN85.dnsmgr.net]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_SHORT(-0.31)[-0.308,0]; R_SPF_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:13868, ipnet:69.59.192.0/19, country:US]; MID_RHS_MATCH_FROM(0.00)[]; IP_SCORE(-0.02)[country: US(-0.09)] X-Rspamd-Server: mx1.freebsd.org X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 19 Nov 2018 15:51:22 -0000 > It really isn't It is all relative. You have to take into perspective just what it is your "computing" and how much state it should need to do that "computation". Modern systems and software have become very wasteful as memory was "cheap". With 10nM getting the better of Intel, and DARPA pushing towards 5nM the cheapness factor is rapidly erroding. 8GB is a huge amount of memory if I am trying to play astroids on a 640x480 display, it is a drop in the bucket if I am trying to do fluid dynamics of a aircraft wing. > On 19/11/2018 10:24, Wojciech Puchar wrote: > >> can go a long way. Having said that, it's been a while since I've had > >> to do this. The updates made to ZFS ARC and NUMA have allowed me to > >> rely on the algorithms baked into FreeBSD. My 8 GB systems have > >> performed rather well. > > > > 8GB is LOT LOT LOT of memory. > > My diskless boot server laptop is running ZFS and now since updated to 12.0Beta4 NUMA too and is rather happy in its 2GB of memory. The work load fits niceless into this footprint. I probably would not want to fire up X11 and Firefox as a daily browswer on it, but the fact is it can also do that without too much pain. -- Rod Grimes rgrimes@freebsd.org