From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from digeo-nav01.digeo.com (digeo-nav01.digeo.com [192.168.1.233]) by packet.digeo.com (8.9.3+Sun/8.9.3) with SMTP id AAA01934 for ; Wed, 26 Feb 2003 00:33:01 -0800 (PST) Date: Wed, 26 Feb 2003 00:33:34 -0800 From: Andrew Morton Subject: Re: Silly question: How to map a user space page in kernel space? Message-Id: <20030226003334.7e85d5b2.akpm@digeo.com> In-Reply-To: <9860000.1046238956@[10.10.2.4]> References: <9860000.1046238956@[10.10.2.4]> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: "Martin J. Bligh" Cc: inaky.perez-gonzalez@intel.com, linux-mm@kvack.org List-ID: "Martin J. Bligh" wrote: > > But be aware that pagefaulting inside kmap_atomic is bad - you can get > blocked and rescheduled, so touching user pages, etc is dangerous. That's true in 2.4. In 2.5 a copy_foo_user() inside kmap_atomic() will just return a short copy while remaining atomic. See mm/filemap.c:filemap_copy_from_user() -- 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: aart@kvack.org