From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e1.ny.us.ibm.com (8.12.11/8.12.11) with ESMTP id jA7LmfT2026183 for ; Mon, 7 Nov 2005 16:48:41 -0500 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay02.pok.ibm.com (8.12.10/NCO/VERS6.7) with ESMTP id jA7LmfMf123048 for ; Mon, 7 Nov 2005 16:48:41 -0500 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11/8.13.3) with ESMTP id jA7Lmeo3001606 for ; Mon, 7 Nov 2005 16:48:41 -0500 Subject: Re: [RFC 2/2] Hugetlb COW From: Adam Litke In-Reply-To: <1131399533.25133.104.camel@localhost.localdomain> References: <1131397841.25133.90.camel@localhost.localdomain> <1131399533.25133.104.camel@localhost.localdomain> Content-Type: text/plain Date: Mon, 07 Nov 2005 15:47:55 -0600 Message-Id: <1131400076.25133.110.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, David Gibson , hugh@veritas.com, rohit.seth@intel.com, "Chen, Kenneth W" , akpm@osdl.org List-ID: On Mon, 2005-11-07 at 15:38 -0600, Adam Litke wrote: > [RFC] COW for hugepages > (Patch originally from David Gibson ) > > This patch implements copy-on-write for hugepages, hence allowing > MAP_PRIVATE mappings of hugetlbfs. > > This is chiefly useful for cases where we want to use hugepages > "automatically" - that is to map hugepages without the knowledge of > the code in the final application (either via kernel hooks, or with > LD_PRELOAD). We can use various heuristics to determine when > hugepages might be a good idea, but changing the semantics of > anonymous memory from MAP_PRIVATE to MAP_SHARED without the app's > knowledge is clearly wrong. I forgot to mention in the original post that this patch is currently broken on ppc64 due to a problem with update_mmu_cache(). The proper fix is understood but backed up behind the powerpc merge activity. -- Adam Litke - (agl at us.ibm.com) IBM Linux Technology Center -- 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