From owner-freebsd-current@freebsd.org Sat Apr 2 08:08:04 2016 Return-Path: Delivered-To: freebsd-current@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 54130B0048F for ; Sat, 2 Apr 2016 08:08:04 +0000 (UTC) (envelope-from cy.schubert@komquats.com) Received: from smtp-out-no.shaw.ca (smtp-out-no.shaw.ca [64.59.134.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 1F63012BD; Sat, 2 Apr 2016 08:08:03 +0000 (UTC) (envelope-from cy.schubert@komquats.com) Received: from spqr.komquats.com ([96.50.22.10]) by shaw.ca with SMTP id mGb5adCuiQeymmGb6aN4GM; Sat, 02 Apr 2016 02:07:57 -0600 X-Authority-Analysis: v=2.2 cv=H9KZ+KQi c=1 sm=1 tr=0 a=jvE2nwUzI0ECrNeyr98KWA==:117 a=jvE2nwUzI0ECrNeyr98KWA==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=kziv93cY1bsA:10 a=zxA2vyXaAAAA:8 a=BWvPGDcYAAAA:8 a=YxBL1-UpAAAA:8 a=6I5d2MoRAAAA:8 a=CXr4gaLU_lRdKpZPUXkA:9 Received: from slippy.cwsent.com (slippy [10.1.1.91]) by spqr.komquats.com (Postfix) with ESMTP id 9C11113751; Sat, 2 Apr 2016 01:07:55 -0700 (PDT) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.15.2/8.15.2) with ESMTP id u3287tgc034452; Sat, 2 Apr 2016 01:07:55 -0700 (PDT) (envelope-from Cy.Schubert@komquats.com) Message-Id: <201604020807.u3287tgc034452@slippy.cwsent.com> X-Mailer: exmh version 2.8.0 04/21/2012 with nmh-1.6 Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.komquats.com/ To: Michael Butler cc: "O. Hartmann" , "K. Macy" , FreeBSD CURRENT Subject: Re: CURRENT slow and shaky network stability In-Reply-To: Message from Michael Butler of "Sat, 26 Mar 2016 13:28:16 -0400." <56F6C6B0.6010103@protected-networks.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sat, 02 Apr 2016 01:07:55 -0700 X-CMAE-Envelope: MS4wfFYUbmaLfveULuS0koV92QZN/iQfhvFRf0d04PRojky/swWD8umIyG4Dib+QeRagWunilZOLBWwLffiH+aKt0QVqKJKc5CjJLUYIkkcjN/fPntsz5gKQ 1curYd7ccbdY4gsOfJqJaAMjvGv+ZMG1OCBcJD7p3K+llWBfavnQong29EOYpTSGU0nUd31+dW1SA7bd6n0b315RMVf4BTIzM2ud7g+QsRFKh6k6LCRlL5JA JQfLVPwl8lsCwRi6FlvnN4pNY4aNiVLR2MZn8rXBa/M5sc44uInZFGPxzNb7ANFD X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Apr 2016 08:08:04 -0000 In message <56F6C6B0.6010103@protected-networks.net>, Michael Butler writes: > -current is not great for interactive use at all. The strategy of > pre-emptively dropping idle processes to swap is hurting .. big time. FreeBSD doesn't "preemptively" or arbitrarily push pages out to disk. LRU doesn't do this. > > Compare inactive memory to swap in this example .. > > 110 processes: 1 running, 108 sleeping, 1 zombie > CPU: 1.2% user, 0.0% nice, 4.3% system, 0.0% interrupt, 94.5% idle > Mem: 474M Active, 1609M Inact, 764M Wired, 281M Buf, 119M Free > Swap: 4096M Total, 917M Used, 3178M Free, 22% Inuse To analyze this you need to capture vmstat output. You'll see the free pool dip below a threshold and pages go out to disk in response. If you have daemons with small working sets, pages that are not part of the working sets for daemons or applications will eventually be paged out. This is not a bad thing. In your example above, the 281 MB of UFS buffers are more active than the 917 MB paged out. If it's paged out and never used again, then it doesn't hurt. However the 281 MB of buffers saves you I/O. The inactive pages are part of your free pool that were active at one time but now are not. They may be reclaimed and if they are, you've just saved more I/O. Top is a poor tool to analyze memory use. Vmstat is the better tool to help understand memory use. Inactive memory isn't a bad thing per se. Monitor page outs, scan rate and page reclaims. -- Cheers, Cy Schubert or FreeBSD UNIX: Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.