From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Date: Tue, 25 Mar 2008 12:05:53 +0000 Subject: Re: larger default page sizes... Message-Id: <87wsnrgg9q.fsf@basil.nowhere.org> List-Id: References: <20080321.145712.198736315.davem@davemloft.net> <20080324.133722.38645342.davem@davemloft.net> <18408.29107.709577.374424@cargo.ozlabs.ibm.com> In-Reply-To: <18408.29107.709577.374424@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Paul Mackerras Cc: David Miller , clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, torvalds@linux-foundation.org Paul Mackerras writes: > > 4kB pages: 444.051s user + 34.406s system time > 64kB pages: 419.963s user + 16.869s system time > > That's nearly 10% faster with 64kB pages -- on a kernel compile. Do you have some idea where the improvement mainly comes from? Is it TLB misses or reduced in kernel overhead? Ok I assume both play together but which part of the equation is more important? -Andi From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754768AbYCYMGK (ORCPT ); Tue, 25 Mar 2008 08:06:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753341AbYCYMF5 (ORCPT ); Tue, 25 Mar 2008 08:05:57 -0400 Received: from smtp-out02.alice-dsl.net ([88.44.60.12]:17017 "EHLO smtp-out02.alice-dsl.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753278AbYCYMF5 (ORCPT ); Tue, 25 Mar 2008 08:05:57 -0400 To: Paul Mackerras Cc: David Miller , clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, torvalds@linux-foundation.org Subject: Re: larger default page sizes... References: <20080321.145712.198736315.davem@davemloft.net> <20080324.133722.38645342.davem@davemloft.net> <18408.29107.709577.374424@cargo.ozlabs.ibm.com> From: Andi Kleen Date: 25 Mar 2008 13:05:53 +0100 In-Reply-To: <18408.29107.709577.374424@cargo.ozlabs.ibm.com> Message-ID: <87wsnrgg9q.fsf@basil.nowhere.org> User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-OriginalArrivalTime: 25 Mar 2008 11:59:16.0522 (UTC) FILETIME=[A67468A0:01C88E6F] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul Mackerras writes: > > 4kB pages: 444.051s user + 34.406s system time > 64kB pages: 419.963s user + 16.869s system time > > That's nearly 10% faster with 64kB pages -- on a kernel compile. Do you have some idea where the improvement mainly comes from? Is it TLB misses or reduced in kernel overhead? Ok I assume both play together but which part of the equation is more important? -Andi From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: larger default page sizes... References: <20080321.145712.198736315.davem@davemloft.net> <20080324.133722.38645342.davem@davemloft.net> <18408.29107.709577.374424@cargo.ozlabs.ibm.com> From: Andi Kleen Date: 25 Mar 2008 13:05:53 +0100 In-Reply-To: <18408.29107.709577.374424@cargo.ozlabs.ibm.com> Message-ID: <87wsnrgg9q.fsf@basil.nowhere.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Mackerras Cc: David Miller , clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, torvalds@linux-foundation.org List-ID: Paul Mackerras writes: > > 4kB pages: 444.051s user + 34.406s system time > 64kB pages: 419.963s user + 16.869s system time > > That's nearly 10% faster with 64kB pages -- on a kernel compile. Do you have some idea where the improvement mainly comes from? Is it TLB misses or reduced in kernel overhead? Ok I assume both play together but which part of the equation is more important? -Andi -- 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