From owner-freebsd-arm@freebsd.org Fri Jun 15 23:36:21 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 765671020F94 for ; Fri, 15 Jun 2018 23:36:21 +0000 (UTC) (envelope-from fbsd@www.zefox.net) Received: from www.zefox.net (www.zefox.net [50.1.20.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "www.zefox.org", Issuer "www.zefox.org" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id C1F626883D for ; Fri, 15 Jun 2018 23:36:20 +0000 (UTC) (envelope-from fbsd@www.zefox.net) Received: from www.zefox.net (localhost [127.0.0.1]) by www.zefox.net (8.15.2/8.15.2) with ESMTPS id w5FNaQhF041654 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 15 Jun 2018 16:36:27 -0700 (PDT) (envelope-from fbsd@www.zefox.net) Received: (from fbsd@localhost) by www.zefox.net (8.15.2/8.15.2/Submit) id w5FNaP0P041653; Fri, 15 Jun 2018 16:36:25 -0700 (PDT) (envelope-from fbsd) Date: Fri, 15 Jun 2018 16:36:25 -0700 From: bob prohaska To: Warner Losh Cc: Mark Millard , "freebsd-arm@freebsd.org" , "Rodney W. Grimes" , bob prohaska Subject: Re: GPT vs MBR for swap devices Message-ID: <20180615233625.GA41147@www.zefox.net> References: <20180614175622.GC35161@www.zefox.net> <201806142110.w5ELAL0N046840@pdx.rh.CN85.dnsmgr.net> <20180615035225.GA37370@www.zefox.net> <20180615051527.GB37370@www.zefox.net> <834EA7A6-B567-436F-96B2-0C75FACA3FF9@yahoo.com> <20180615154334.GA39777@www.zefox.net> <20180615164202.GB39777@www.zefox.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Jun 2018 23:36:21 -0000 On Fri, Jun 15, 2018 at 11:21:01AM -0600, Warner Losh wrote: > On Fri, Jun 15, 2018 at 10:42 AM, bob prohaska wrote: > > > On Fri, Jun 15, 2018 at 09:57:17AM -0600, Warner Losh wrote: > > > > > gstat -Bd -I 10 -f > > > gstat-swap-data.dat > > > Could a longer interval, maybe one or ten seconds, and perhaps the -a flag to reduce file size produce useful results? Given the way gstat output is formatted it does not look easy to search, except in small amounts by eye. > > > would be how I'd recommend collecting it. This file may get kinda big > > > depending how long it takes to trigger the weird state. I'm hoping that > > if > > > you put this on a known good device, we'll power through the issues. We > > > might not get perfect correlation with this, but the data should show all > > > kinds of crazy before the system drives off the cliff if I'm right, so we > > > don't need perfect data. > > > > > > > Apologies, we spoke of gstat earlier. I lost the distinction between > > gstat and vmstat. In the case at hand the possible swap devices are > > > > /dev/da0b (this is the one causing trouble) > > /dev/mmcsd0s3b > > /dev/mmcsd0s3d > > > > > > what would the correct look like? > > > > I'd just use -f '^da0b$' for each of the devices. > So, ignore the SD flash for now? > > > Is there any indication why problems seen on the RPI3 do not seem > > apparent on an RPI2? A 2 GB USB flash swap partition seems to work > > successfully on the Pi2. > > > > Interesting. The only thing I can think of is different OOM tuning levels. > But if anything, I'd expect more trouble on the RPi2 than the RPi3. So that > might also point to a difference in USB and/or VM things. It would be > interesting to see if we see a significant difference in the graphs between > the two for the same physical drive. I'd have expected, like you, that this > would be reproducible between the two. > The Pi2 vs Pi3 comparison is less fair than I indicated; the Pi2 is running 11.2-PRERELEASE FreeBSD 11.2-PRERELEASE #0 r335072, while the Pi3 is running 12.0-CURRENT FreeBSD 12.0-CURRENT #0 r334939. Both Pi2 and Pi3 are using 64 GB Sandisk Extreme USB flash drives, but the unit on the Pi3 is about a year newer. I'd expect that to help, rather than hurt, but.... I'll try logging gstat output on the Pi2 as-is during a clean-start buildworld and see what happens. Thanks for all your help! bob prohaska