From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: [PATCH 0/23] File descriptor hot-unplug support v2 Date: Mon, 08 Jun 2009 23:42:53 -0700 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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Al Viro , Miklos Szeredi , 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 To: Linus Torvalds Return-path: In-Reply-To: (Linus Torvalds's message of "Mon\, 8 Jun 2009 12\:18\:41 -0700 \(PDT\)") Sender: linux-pci-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Linus Torvalds writes: > 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. That sounds doable. Has that code been merged yet? I took a quick look and it didn't see anyone breaking out of page fault with a signal or code to really handle that. Eric