From owner-freebsd-arm@freebsd.org Thu Jun 14 17:56:10 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 8B2D5101861A for ; Thu, 14 Jun 2018 17:56:10 +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 0A5D178114 for ; Thu, 14 Jun 2018 17:56:09 +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 w5EHuMi8035726 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 14 Jun 2018 10:56:23 -0700 (PDT) (envelope-from fbsd@www.zefox.net) Received: (from fbsd@localhost) by www.zefox.net (8.15.2/8.15.2/Submit) id w5EHuMln035725; Thu, 14 Jun 2018 10:56:22 -0700 (PDT) (envelope-from fbsd) Date: Thu, 14 Jun 2018 10:56:22 -0700 From: bob prohaska To: "Rodney W. Grimes" Cc: Tom Vijlbrief , "freebsd-arm@freebsd.org" , bob prohaska Subject: Re: GPT vs MBR for swap devices Message-ID: <20180614175622.GC35161@www.zefox.net> References: <20180614164436.GA35161@www.zefox.net> <201806141653.w5EGrvpR045732@pdx.rh.CN85.dnsmgr.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201806141653.w5EGrvpR045732@pdx.rh.CN85.dnsmgr.net> 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: Thu, 14 Jun 2018 17:56:10 -0000 On Thu, Jun 14, 2018 at 09:53:57AM -0700, Rodney W. Grimes wrote: > > I would be very interested in seeing if resizing the swap partition > in the example that greatly exceeds what the system expects as a > max total swap helps to bring the OOM issue under control. > The swap partitions at my immediate disposal are 1 GB USB flash 1 GB microSD flash 2 GB microSD flash 3 GB USB mechanical What combination is apt to be most informative? My original intent was to use 1 GB USB flash plus 1 GB microSD flash in hopes of a speed gain from interleaving, but maybe that's no longer realistic. Anything over 3 GB total causes the "too much swap" warning and I've never observed more than about 1.2 GB of swap in use. > I think the state of things is such that if you use up the > max usable swap space on the first swap device, only that > swap device well ever be used. I do not believe there is > any attempts what so ever to split the allocation up so > that you use the first fraction of each device. > Swap usage seem to be spread among active partitions, though how they're weighted is unclear to me. In days of yore there was a little note about "interleaved" in swapinfo reports, but I don't recall seeing that for a loong time. Maybe that feature has gone away..... Thanks for reading, bob prohaska