From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Neukum Subject: Re: [RFC] recursive pagetables for x86 PAE Date: Sat, 14 Jun 2003 13:27:48 +0200 References: <1055540875.3531.2581.camel@nighthawk> In-Reply-To: <1055540875.3531.2581.camel@nighthawk> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200306141327.48649.oliver@neukum.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Hansen , Linux Kernel Mailing List , linux-mm Cc: "Martin J. Bligh" , William Lee Irwin III List-ID: Am Freitag, 13. Juni 2003 23:47 schrieb Dave Hansen: > When you have lots of tasks, the pagetables start taking up lots of > lowmem. We have the ability to push the PTE pages into highmem, but > that exacts a penalty from the atomic kmaps which, depending on > workload, can be a 10-15% performance hit. > > The following patches implement something which we like to call UKVA. > It's a Kernel Virtual Area which is private to a process, just like > Userspace. You can put any process-local data that you want in the > area. But, for now, I just put PTE pages in there. If you put only such pages there, do you really want that memory to be per task? IMHO it should be per memory context to aid threading performance. Secondly, doesn't this scream for using large pages? Regards Oliver -- 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