From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 3 Jul 2003 15:48:21 +0200 From: Andrea Arcangeli Subject: Re: What to expect with the 2.6 VM Message-ID: <20030703134821.GD23578@dualathlon.random> References: <20030703125839.GZ23578@dualathlon.random> 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: Rik van Riel Cc: William Lee Irwin III , "Martin J. Bligh" , Mel Gorman , Linux Memory Management List , Linux Kernel Mailing List List-ID: On Thu, Jul 03, 2003 at 09:06:32AM -0400, Rik van Riel wrote: > On Thu, 3 Jul 2003, Andrea Arcangeli wrote: > > > even if you don't use largepages as you should, the ram cost of the pte > > is nothing on 64bit archs, all you care about is to use all the mhz and > > tlb entries of the cpu. > > That depends on the number of Oracle processes you have. well, that wasn't necessairly a database but ok. > Say that page tables need 0.1% of the space of the virtual > space they map. With 1000 Oracle users you'd end up needing > as much memory in page tables as your shm segment is large. so just add more ram, ram is cheaper than cpu power (I mean, on 64bit) > Of course, in this situation either the application should > use large pages or the kernel should simply reclaim the as you say, it should definitely use largepages if it's such kind of usage, so the whole point of saving pte space is void. it should use largepages even if it's not "many tasks mapping the shm", but just a single task mapping some huge ram. > Agreed on that. Please let the monstrosity die together > with 32 bit machines ;) Indeed ;) Andrea -- 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: aart@kvack.org