From owner-freebsd-current Tue Apr 23 23:20:13 2002 Delivered-To: freebsd-current@freebsd.org Received: from perd1.estpak.ee (ld1.estpak.ee [194.126.101.98]) by hub.freebsd.org (Postfix) with ESMTP id 2A1C737B423; Tue, 23 Apr 2002 23:19:45 -0700 (PDT) Received: from myhakas.estpak.ee (myhakas.estpak.ee [194.126.115.54]) by perd1.estpak.ee (Postfix) with ESMTP id AF4D38808C; Wed, 24 Apr 2002 09:18:18 +0300 (EEST) Received: from myhakas.estpak.ee (localhost [127.0.0.1]) by myhakas.estpak.ee (8.12.2/8.12.2) with ESMTP id g3O6IIC9033315; Wed, 24 Apr 2002 09:18:18 +0300 (EEST) (envelope-from vallo@myhakas.estpak.ee) Received: (from vallo@localhost) by myhakas.estpak.ee (8.12.2/8.12.2/Submit) id g3O6GrYl033291; Wed, 24 Apr 2002 09:16:53 +0300 (EEST) Date: Wed, 24 Apr 2002 09:16:53 +0300 From: Vallo Kallaste To: "Marc G. Fournier" , Terry Lambert , freebsd-current@FreeBSD.ORG, freebsd-stable@FreeBSD.ORG Subject: Re: FreeBSD 4.5-STABLE not easily scalable to large servers ... ? Message-ID: <20020424061653.GA33245@myhakas.estpak.ee> Reply-To: kalts@estpak.ee References: <3CC4C683.F9AEF14E@mindspring.com> <20020423092909.N1721-100000@mail1.hub.org> <20020423184534.GA30212@myhakas.estpak.ee> <20020423214011.B3593@HAL9000.wox.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020423214011.B3593@HAL9000.wox.org> User-Agent: Mutt/1.5.0i Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Tue, Apr 23, 2002 at 09:40:11PM -0700, David Schultz wrote: > > Userspace processes will allocate memory from UVA space and can > > grow over 1GB of size if needed by swapping. You can certainly > > have more than one over-1GB process going on at the same time, > > but swapping will constrain your performance. > > It isn't a performance constraint. 32-bit architectures have > 32-bit pointers, so in the absence of segmentation tricks, a > virtual address space can only contain 2^32 = 4G locations. If > the kernel gets 3 GB of that, the maximum amount of memory that > any individual user process can use is 1 GB. If you had, say, 4 > GB of physical memory, a single user process could not use it all. > Swap increases the total amount of memory that *all* processes can > allocate by pushing some of the pages out of RAM and onto the > disk, but it doesn't increase the total amount of memory that a > single process can address. Thank you, Terry and David, now I grasp how it should work (I hope). I really miss some education, but that's life. -- Vallo Kallaste kalts@estpak.ee To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message