Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753316AbZFHTUm (ORCPT ); Mon, 8 Jun 2009 15:20:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752173AbZFHTUe (ORCPT ); Mon, 8 Jun 2009 15:20:34 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:48298 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750725AbZFHTUd (ORCPT ); Mon, 8 Jun 2009 15:20:33 -0400 Date: Mon, 8 Jun 2009 12:18:41 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Al Viro cc: Miklos Szeredi , ebiederm@xmission.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, hugh@veritas.com, tj@kernel.org, adobriyan@gmail.com, alan@lxorguk.ukuu.org.uk, gregkh@suse.de, npiggin@suse.de, akpm@linux-foundation.org, hch@infradead.org Subject: Re: [PATCH 0/23] File descriptor hot-unplug support v2 In-Reply-To: <20090608185041.GN8633@ZenIV.linux.org.uk> Message-ID: References: <20090606080334.GA15204@ZenIV.linux.org.uk> <20090608162913.GL8633@ZenIV.linux.org.uk> <20090608175018.GM8633@ZenIV.linux.org.uk> <20090608185041.GN8633@ZenIV.linux.org.uk> 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 Content-Length: 918 Lines: 22 On Mon, 8 Jun 2009, Al Viro wrote: > > Sure, even though I'm not at all certain that copy_from_user() is that easy. > We can make locking current->mm in there interruptible, all right, but that's > only a part of the answer - even aside of the allocations, we'd need vma > ->fault() interruptible as well, which leads to interruptible instances of > ->readpage(), with all the fun _that_ would be. We already have all that - the NFS people wanted it. More importantly, you don't actually need to interrupt readpage itself - you just need to stop _waiting_ on it. So in your fault handler, just stop waiting, and instead just return FAULT_RETRY or whatever. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/