From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 18 Dec 2004 03:06:08 -0800 From: William Lee Irwin III Subject: Re: [PATCH 4/10] alternate 4-level page tables patches Message-ID: <20041218110608.GJ771@holomorphy.com> References: <41C3D453.4040208@yahoo.com.au> <41C3D479.40708@yahoo.com.au> <41C3D48F.8080006@yahoo.com.au> <41C3D4AE.7010502@yahoo.com.au> <41C3D4C8.1000508@yahoo.com.au> <41C3F2D6.6060107@yahoo.com.au> <20041218095050.GC338@wotan.suse.de> <41C40125.3060405@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41C40125.3060405@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andi Kleen , Linux Memory Management , Hugh Dickins , Linus Torvalds , Andrew Morton List-ID: On Sat, Dec 18, 2004 at 09:06:29PM +1100, Nick Piggin wrote: > Yes I thought about that a bit too. > Note that this (4/10) patch should give perfect garbage collection too > (modulo bugs). The difference is in where the overheads lie. I suspect > refcounting may be too much overhead (at least, SMP overhead); especially > in light of Christoph's results. If this were so, then clear_page_tables() during process destruction would be unnecessary. detach_vmas_to_be_unmapped() makes additional work for such schemes, but even improvements are still rather helpful. On Sat, Dec 18, 2004 at 09:06:29PM +1100, Nick Piggin wrote: > Although I think it would enable you to do page table reclaim when > reclaiming mapped, file backed pages quite easily... but I'm not sure if > that is enough to offset the slowdowns. That would be a far more appropriate response to high multiprogramming levels than what is now done. -- wli -- 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