From owner-freebsd-hackers Thu Mar 22 8:19:48 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from postfix.conectiva.com.br (perninha.conectiva.com.br [200.250.58.156]) by hub.freebsd.org (Postfix) with ESMTP id EED6137B71F for ; Thu, 22 Mar 2001 08:19:45 -0800 (PST) (envelope-from riel@conectiva.com.br) Received: from burns.conectiva (burns.conectiva [10.0.0.4]) by postfix.conectiva.com.br (Postfix) with SMTP id 5952116EEE for ; Thu, 22 Mar 2001 13:19:42 -0300 (EST) Received: (qmail 21491 invoked by uid 0); 22 Mar 2001 16:19:04 -0000 Received: from dial11.ras.conectiva (HELO imladris.rielhome.conectiva) (root@10.0.8.11) by burns.conectiva with SMTP; 22 Mar 2001 16:19:04 -0000 Received: from localhost (IDENT:riel@localhost [127.0.0.1]) by imladris.rielhome.conectiva (8.11.2/8.11.2) with ESMTP id f2MEx9h24575; Thu, 22 Mar 2001 11:59:09 -0300 Date: Thu, 22 Mar 2001 11:59:09 -0300 (BRST) From: Rik van Riel X-Sender: riel@imladris.rielhome.conectiva To: thinker Cc: hackers@FreeBSD.ORG Subject: Re: tuning a VERY heavily (30.0) loaded s cerver In-Reply-To: <20010322191057.A46607@hell.branda.to> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, 22 Mar 2001, thinker wrote: > On Wed, Mar 21, 2001 at 04:14:32PM -0300, Rik van Riel wrote: > > The (maybe too lightweight) structure I have in my patch > > looks like this: > > > > struct pte_chain { > > struct pte_chain * next; > > pte_t * ptep; > > }; > > > > Each pte_chain hangs off a page of physical memory and the > > ptep is a pointer to a page table entry. > > > > The page struct of the page table page itself is used to > > note down which address space and offset we have. This means > > that FreeBSD's pv_pmap, pv_va and pv_ptem are in the page > > table page and NOT in each pte_chain structure... > > How about portability? It maybe efficient, but it is not easy > to port to other platforms. IIRC the pmap layer is in the architecture-dependent code in the BSDs. For Linux we have forward pagetables in every architecture, whether it be in software or hardware. They turn out to be quite adequate as an alternative to vnodes ;) regards, Rik -- Virtual memory is like a game you can't win; However, without VM there's truly nothing to lose... http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com.br/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message