From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268425AbUHLGva (ORCPT ); Thu, 12 Aug 2004 02:51:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268431AbUHLGva (ORCPT ); Thu, 12 Aug 2004 02:51:30 -0400 Received: from holomorphy.com ([207.189.100.168]:43657 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S268425AbUHLGu5 (ORCPT ); Thu, 12 Aug 2004 02:50:57 -0400 Date: Wed, 11 Aug 2004 23:50:47 -0700 From: William Lee Irwin III To: Jeff Dike Cc: akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] 2.6.8-rc4-mm1 - UML fixes Message-ID: <20040812065047.GG11200@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Jeff Dike , akpm@osdl.org, linux-kernel@vger.kernel.org References: <200408120415.i7C4FWJd010494@ccure.user-mode-linux.org> <20040812033012.GE11200@holomorphy.com> <200408120541.i7C5fIJd010913@ccure.user-mode-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200408120541.i7C5fIJd010913@ccure.user-mode-linux.org> User-Agent: Mutt/1.5.6+20040722i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org wli@holomorphy.com said: >> Out of curiosity, why are you allocating 4*PAGE_SIZE for the stack if >> you're only going to use 2*PAGE_SIZE of it? I saw no other users for >> the rest of ->thread_info offhand. On Thu, Aug 12, 2004 at 01:41:18AM -0400, Jeff Dike wrote: > Well, that's slightly misleading. The other two pages (minus the thread_info) > are available for stack if needed. UML stacks are somewhat larger than the > native kernel stacks because of the userspace signal frames, so I allocate > 4 pages for now to be safe. This might confuse CONFIG_DEBUG_PAGEALLOC, which uses THREAD_SIZE to detect the end of the kernel stack in store_stackinfo() in mm/slab.c and kstack_end() in include/linux/sched.h, and the sizing heuristic for max_threads in fork_init(). Also, how is this meant to interoperate with CONFIG_KERNEL_STACK_ORDER? It seems to ignore the setting from the config option. -- wli