From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752505AbZEaXQT (ORCPT ); Sun, 31 May 2009 19:16:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751223AbZEaXQL (ORCPT ); Sun, 31 May 2009 19:16:11 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:48885 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750866AbZEaXQK (ORCPT ); Sun, 31 May 2009 19:16:10 -0400 Date: Sun, 31 May 2009 16:15:50 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Andrew Morton cc: Alexey Dobriyan , Matt Helsley , xemul@parallels.com, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, dave@linux.vnet.ibm.com, mingo@elte.hu Subject: Re: [PATCH 14/38] Remove struct mm_struct::exe_file et al In-Reply-To: <20090531151953.8f8b14b5.akpm@linux-foundation.org> Message-ID: References: <20090526113618.GJ28083@us.ibm.com> <20090526162415.fb9cefef.akpm@linux-foundation.org> <20090531215427.GA29534@x200.localdomain> <20090531151953.8f8b14b5.akpm@linux-foundation.org> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 31 May 2009, Andrew Morton wrote: > > What I always find a bit weird is that an MM container is used as the > central point for a number of sched obects. But it's logical, given > that the never-before-stated definition of a heavyweight process is > "thing which share a VM". It has nothing to do with "heavy-weight process" or anything else. The thing is, from a scheduling standpoint, one of the primary performance concerns in the TLB switch. And there's a 1:1 relationship between TLB switch and MM container, modulo the issue of kernel tasks (and those obviously "borrow" approproate MM structs to avoid the switch). So it's not weird at all. It's very direct, and a very straightforward and obvious relationship. Linus