From owner-freebsd-virtualization@freebsd.org Sat Dec 2 05:10:23 2017 Return-Path: Delivered-To: freebsd-virtualization@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 3FF7BDF3438 for ; Sat, 2 Dec 2017 05:10:23 +0000 (UTC) (envelope-from kmacybsd@gmail.com) Received: from mail-oi0-f54.google.com (mail-oi0-f54.google.com [209.85.218.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 109491ABC for ; Sat, 2 Dec 2017 05:10:22 +0000 (UTC) (envelope-from kmacybsd@gmail.com) Received: by mail-oi0-f54.google.com with SMTP id t81so8531208oih.13 for ; Fri, 01 Dec 2017 21:10:22 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Gqy4fuOVf6a9tYoqEELBndGiioGEknKXz38KZOnjBAM=; b=XMkA2hJfgT0fgZ7B7U+mUJwF+qQsWfgn4P+KFE0snNyUmR1Bh2ORm/1vVUNUkmSXS0 LymQdhpmUYQCOkwy1fn1MOLc6wCGbrheNRnvLHaI/s9P4bb68tBxGP97TOwWqq8T9II6 lFTarrCzyjwN3ELIFnMu4Z2LrboLqYKVoqedMHB0m6WdRWNGaX7mCxZ8NLgJVlqMgfTc wFUSq6wZaflvXu75A7eavSOOGSQl6pvysv5BhnlBVLEKi8cImfQ9hUMeI8U19gMNqh6R eyoG2/bAoa0IhjAPIiWBglKvSOMiK14SGz1XUfgDnFLyXGowgubp7/RaBZZYPAYgg4NO YCmA== X-Gm-Message-State: AJaThX775RaOz4job9GXYumqfJQxosnrhX2RoDROfZG3fIz9ly0uh9ek D3F+Z+jYy8VJiDKyUGdN9b+c+gnV72sLgXDFcos= X-Google-Smtp-Source: AGs4zMbZGv5kbBziM9cNT7WlP9tu9TAKigb2VnGYcnmzc+nwgRA5fu/avvP8RBt0Pdxs4Yv1RZYlTFNj4ox+9VjHPJI= X-Received: by 10.202.191.6 with SMTP id p6mr5356365oif.311.1512191416124; Fri, 01 Dec 2017 21:10:16 -0800 (PST) MIME-Version: 1.0 References: <5bb5649f-5785-7baf-6871-625d1f63bd8b@ShaneWare.Biz> <201712020402.vB242DaJ032505@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <201712020402.vB242DaJ032505@pdx.rh.CN85.dnsmgr.net> From: "K. Macy" Date: Sat, 02 Dec 2017 05:10:05 +0000 Message-ID: Subject: Re: bhyve uses all available memory during IO-intensive operations To: "Rodney W. Grimes" Cc: Shane Ambler , freebsd-virtualization@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Dec 2017 05:10:23 -0000 On Fri, Dec 1, 2017 at 20:02 Rodney W. Grimes < freebsd-rwg@pdx.rh.cn85.dnsmgr.net> wrote: > > On 02/12/2017 08:11, Dustin Wenz wrote: > > > > > > The commit history shows that chyves defaults to -S if you are > > > hosting from FreeBSD 10.3 or later. I'm sure they had a reason for > > > doing that, but I don't know what that would be. It seems to an > > > inefficient use of main memory if you need to run a lot of VMs. > > > > It sounds like a reasonable solution to a problem. If host memory is > > full it swaps some out, so a bhyve might have free mem but some could be > > swapped out by the host. If the bhyve is out of mem, it's system swaps > > to it's disk, so the host swaps it back in so that the bhyve can then > > swap it to its disk... > > > > Wiring bhyve ram might be a reasonable solution as long as the hosts > > physical ram isn't over allocated by bhyve guests. > > > > The best solution would involve a host and guest talking to each other > > about used mem, but that would break the whole virtual machine illusion. > > At the least it would involve a system telling the hardware what memory > > is used and what is not, which just isn't something any system does. > > Maybe that is an idea for the vm guest aware systems of the future. > > Its actually old technology, its called the memory balloon driver, > but bhyve does not have that functionality, yet. > > The virtio ballon driver is already there. Implementing a kernel backend for it would be trivial. In kernel virtio-net and virtio-p9fs backends are already well underway. -M > -- > Rod Grimes > rgrimes@freebsd.org > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to " > freebsd-virtualization-unsubscribe@freebsd.org" >