From owner-freebsd-hackers@FreeBSD.ORG Thu Sep 11 04:28:03 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5DB4D106567A for ; Thu, 11 Sep 2008 04:28:03 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from QMTA08.emeryville.ca.mail.comcast.net (qmta08.emeryville.ca.mail.comcast.net [76.96.30.80]) by mx1.freebsd.org (Postfix) with ESMTP id 41B268FC0A for ; Thu, 11 Sep 2008 04:28:02 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from OMTA12.emeryville.ca.mail.comcast.net ([76.96.30.44]) by QMTA08.emeryville.ca.mail.comcast.net with comcast id DGLD1a0010x6nqcA8GU2pY; Thu, 11 Sep 2008 04:28:02 +0000 Received: from koitsu.dyndns.org ([67.180.253.227]) by OMTA12.emeryville.ca.mail.comcast.net with comcast id DGU11a00G4v8bD78YGU1gx; Thu, 11 Sep 2008 04:28:02 +0000 X-Authority-Analysis: v=1.0 c=1 a=QycZ5dHgAAAA:8 a=0Rd2YH6fUOQvkwFQlekA:9 a=L6K6_LiR4vsDFuWi2F4A:7 a=Bi3p0S33P6UKe8ng53KumEo9o_UA:4 a=EoioJ0NPDVgA:10 a=LY0hPdMaydYA:10 Received: by icarus.home.lan (Postfix, from userid 1000) id 5092717B81A; Wed, 10 Sep 2008 21:28:01 -0700 (PDT) Date: Wed, 10 Sep 2008 21:28:01 -0700 From: Jeremy Chadwick To: Artem Belevich Message-ID: <20080911042801.GA19245@icarus.home.lan> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Cc: freebsd-hackers@freebsd.org, Alan Cox Subject: Re: Increasing KVM on amd64 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Sep 2008 04:28:03 -0000 On Wed, Sep 10, 2008 at 04:12:25PM -0700, Artem Belevich wrote: > Alan, > > Thanks a lot for the patch. I've applied it to RELENG_7 and it seems > to work great - "make -j8 buildworld" succeeds, linux emulation seems > to work well enough to run linux-sun-jdk14 binaries, ZFS ARC size is > bigger, too. So far I didn't see any ZFS-related KVM shortages either. > > The only problem is that everything is fine as long as vm.kmem_size is > set to less or equal to 4096M. As soon as I set it to 4100M or > anything larger, kernel crashes on startup. I'm unable to capture > exact crash messages as they keep scrolling really fast on the screen > for a few seconds until the box reboots. Unfortunately the box does > not have built-in serial ports, so the messages are gone before I can > see them. :-( > > Is there a way to bump up KVM size even further - beyond 6GB? I've got > a box with 8GB or RAM and would like let ZFS ARC use most of it which > would require pretty large vm.kmem_max to fit it in. I was told fairly recently (a few days ago) that the 6GB limit was increased to 512GB on HEAD/CURRENT. The 6GB limit was during a "transitional" phase of addressing the problem. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |