From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e36.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id m42HFjkf010684 for ; Fri, 2 May 2008 13:15:45 -0400 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m42HFjSN144204 for ; Fri, 2 May 2008 11:15:45 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m42HFio3022759 for ; Fri, 2 May 2008 11:15:45 -0600 Subject: Re: [RFC][PATCH 2/2] Add huge page backed stack support From: Dave Hansen In-Reply-To: <1209693109.8483.23.camel@grover.beaverton.ibm.com> References: <1209693109.8483.23.camel@grover.beaverton.ibm.com> Content-Type: text/plain Date: Fri, 02 May 2008 10:15:42 -0700 Message-Id: <1209748542.7763.39.camel@nimitz.home.sr71.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: ebmunson@us.ibm.com Cc: linux-mm@kvack.org, nacc , mel@csn.ul.ie, andyw List-ID: On Thu, 2008-05-01 at 18:51 -0700, Eric B Munson wrote > The GROWSUP and GROWSDOWN VM flags are turned off because a hugetlb backed > vma is not resizable, so it will be appropriately sized when created. When > a process exceeds stack size it recieves a segfault exactly as it would if it > exceeded the ulimit. This one is *really* subtle. The segfault might behave like breaking a ulimit. But, unlike a ulimit, you can't really work around this particular limitation very easily. This will really suck for anyone that tries to use 64k huge pages on powerpc, right? Are you actually looking to get this included, or are you just trying to play with this? It is useful as a toy as-is, but I think you should look at fixing stack growing before it gets merged anywhere. -- Dave -- 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