From owner-freebsd-current@freebsd.org Sat Apr 2 22:57:58 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 F3719B00459 for ; Sat, 2 Apr 2016 22:57:57 +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 AC2741F12; Sat, 2 Apr 2016 22:57:57 +0000 (UTC) (envelope-from cy.schubert@komquats.com) Received: from spqr.komquats.com ([96.50.22.10]) by shaw.ca with SMTP id mUUKagITjQeymmUUMaOtkM; Sat, 02 Apr 2016 16:57:55 -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=BWvPGDcYAAAA:8 a=zxA2vyXaAAAA:8 a=YxBL1-UpAAAA:8 a=6I5d2MoRAAAA:8 a=_3CExS8uxJAlMTfjgvoA:9 Received: from slippy.cwsent.com (slippy [10.1.1.91]) by spqr.komquats.com (Postfix) with ESMTP id BE89313751; Sat, 2 Apr 2016 15:57:52 -0700 (PDT) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.15.2/8.15.2) with ESMTP id u32MvqRn036767; Sat, 2 Apr 2016 15:57:52 -0700 (PDT) (envelope-from Cy.Schubert@komquats.com) Message-Id: <201604022257.u32MvqRn036767@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: Kevin Oberman cc: "O. Hartmann" , Cy Schubert , Michael Butler , "K. Macy" , FreeBSD CURRENT Subject: Re: CURRENT slow and shaky network stability In-Reply-To: Message from Kevin Oberman of "Sat, 02 Apr 2016 15:28:23 -0700." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sat, 02 Apr 2016 15:57:52 -0700 X-CMAE-Envelope: MS4wfEDv98/CYn9ucwUona34DsLgtXrsq7BUHbGVkrlInxHdzpYArwmPEBY7t86+D908w2OuPwIvEX44JL9oGLrb/cCzgPq5XSyLdQcRthOCu5B6HkhYdcms kLnw8i47mKqBvRlEEohl6M7E8fUgT/f014y65+AHri5M7QBij2FsloZ/W5m4w6SWJDbbjaumZpy/pIHN5WqA9H3dzMlD8c4vbQ2IgGcs83zH4w1vXYpdHZgH Rl+QSpS8Fq9jyx3bnEjp5ceSnUiyIPzow4I7s7A5fkNbdENkb400Qy23RzioB5xAaspDoGI3dJQN4X6XKAlilRrvhmvMxOfoD+EkfmrUHNU= 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 22:57:58 -0000 In message , Kevin Oberman writes: > --089e01176a5d71db0d052f8803c7 > Content-Type: text/plain; charset=UTF-8 > > On Sat, Apr 2, 2016 at 2:19 PM, O. Hartmann > wrote: > > > Am Sat, 2 Apr 2016 11:39:10 +0200 > > "O. Hartmann" schrieb: > > > > > Am Sat, 2 Apr 2016 10:55:03 +0200 > > > "O. Hartmann" schrieb: > > > > > > > Am Sat, 02 Apr 2016 01:07:55 -0700 > > > > Cy Schubert schrieb: > > > > > > > > > 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. > > > > > > > > > > > > > > > > > > I give up! Tried to check via ssh/vmstat what is going on. Last lines > > before broken > > > > pipe: > > > > > > > > [...] > > > > procs memory page disks faults > > cpu > > > > r b w avm fre flt re pi po fr sr ad0 ad1 in sy cs > > us sy id > > > > 22 0 22 5.8G 1.0G 46319 0 0 0 55721 1297 0 4 219 23907 > > 5400 95 5 0 > > > > 22 0 22 5.4G 1.3G 51733 0 0 0 72436 1162 0 0 108 40869 > > 3459 93 7 0 > > > > 15 0 22 12G 1.2G 54400 0 27 0 52188 1160 0 42 148 52192 > > 4366 91 9 0 > > > > 14 0 22 12G 1.0G 44954 0 37 0 37550 1179 0 39 141 86209 > > 4368 88 12 0 > > > > 26 0 22 12G 1.1G 60258 0 81 0 69459 1119 0 27 123 779569 > > 704359 87 13 0 > > > > 29 3 22 13G 774M 50576 0 68 0 32204 1304 0 2 102 507337 > > 484861 93 7 0 > > > > 27 0 22 13G 937M 47477 0 48 0 59458 1264 3 2 112 68131 > > 44407 95 5 0 > > > > 36 0 22 13G 829M 83164 0 2 0 82575 1225 1 0 126 99366 > > 38060 89 11 0 > > > > 35 0 22 6.2G 1.1G 98803 0 13 0 121375 1217 2 8 112 99371 > > 4999 85 15 0 > > > > 34 0 22 13G 723M 54436 0 20 0 36952 1276 0 17 153 29142 > > 4431 95 5 0 > > > > Fssh_packet_write_wait: Connection to 192.168.0.1 port 22: Broken pipe > > > > > > > > > > > > This makes this crap system completely unusable. The server (FreeBSD > > 11.0-CURRENT #20 > > > > r297503: Sat Apr 2 09:02:41 CEST 2016 amd64) in question did > > poudriere bulk job. I > > > > can not even determine what terminal goes down first - another one, > > much more time > > > > idle than the one shwoing the "vmstat 5" output, is still alive! > > > > > > > > i consider this a serious bug and it is no benefit what happened since > > this "fancy" > > > > update. :-( > > > > > > By the way - it might be of interest and some hint. > > > > > > One of my boxes is acting as server and gateway. It utilises NAT, IPFW, > > when it is under > > > high load, as it was today, sometimes passing the network flow from ISP > > into the network > > > for clients is extremely slow. I do not consider this the reason for > > collapsing ssh > > > sessions, since this incident happens also under no-load, but in the > > overall-view onto > > > the problem, this could be a hint - I hope. > > > > I just checked on one box, that "broke pipe" very quickly after I started > > poudriere, > > while it did well a couple of hours before until the pipe broke. It seems > > it's load > > dependend when the ssh session gets wrecked, but more important, after the > > long-haul > > poudriere run, I rebooted the box and tried again with the mentioned > > broken pipe after a > > couple of minutes after poudriere ran. Then I left the box for several > > hours and logged > > in again and checked the swap. Although there was for hours no load or > > other pressure, > > there were 31% of of swap used - still (box has 16 GB of RAM and is > > propelled by a XEON > > E3-1245 V2). > > > > Unless something has changed, just as things are not preemptively swapped > out, they are also not preemptively swapped back in. AFAIK, once a process > is swapped out, it will remain swapped out until/unless it becomes active. > At that time it is swapped in and this can entail a significant delay. If > my laptop is locked and something (usually Chromium) starts eating all of > the memory and processes start swapping out, it can take >5 seconds to get > the unlock window to display. Yes! -- Cheers, Cy Schubert or FreeBSD UNIX: Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.