From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Wienand Date: Wed, 3 May 2006 07:29:15 +1000 Subject: Re: [RFC 2/3] LVHPT - Setup LVHPT Message-ID: <20060502212915.GA12900@cse.unsw.EDU.AU> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: "Luck, Tony" Cc: linux-ia64@vger.kernel.org, linux-mm@kvack.org List-ID: On Tue, May 02, 2006 at 08:03:16AM -0700, Luck, Tony wrote: > + help > + The long format VHPT is an alternative hashed page table. Advantages > + of the long format VHPT are lower memory usage when there are a large > + number of processes in the system. > > Is this really true? Don't you still have all of the 3-level (or 4-level) > tree allocated to keep the machine independent code in mm/memory.c > happy in addition to the big block of memory that you are using on > each cpu for the LVHPT? Where is the saving? Yes that does seem a bit miss-leading. I guess the point was that with short format you dedicate the top areas of your region to page tables for each process, with long format it is static. -i -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org