From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 13 Mar 2007 14:07:22 -0700 (PDT) Message-Id: <20070313.140722.72711732.davem@davemloft.net> Subject: Re: [QUICKLIST 0/4] Arch independent quicklists V2 From: David Miller In-Reply-To: <20070313202125.GO10394@waste.org> References: <20070313200313.GG10459@waste.org> <45F706BC.7060407@goop.org> <20070313202125.GO10394@waste.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org From: Matt Mackall Date: Tue, 13 Mar 2007 15:21:25 -0500 Return-Path: To: mpm@selenic.com Cc: jeremy@goop.org, nickpiggin@yahoo.com.au, akpm@linux-foundation.org, clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: > Because the fan-out is large, the bulk of the work is bringing the last > layer of the tree into cache to find all the pages in the address > space. And there's really no way around that. That's right. And I will note that historically we used to be much worse in this area, as we used to walk the page table tree twice on address space teardown (once to hit the PTE entries, once to free the page tables). Happily it is a one-pass algorithm now. But, within active VMA ranges, we do have to walk all the bits at least one time. -- 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