From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v5 1/4] kvm: Extend irqfd to support level interrupts Date: Wed, 18 Jul 2012 00:26:12 +0300 Message-ID: <20120717212612.GA2018@redhat.com> References: <20120716202711.1752.71007.stgit@bling.home> <20120716203344.1752.14606.stgit@bling.home> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: avi@redhat.com, gleb@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, jan.kiszka@siemens.com To: Alex Williamson Return-path: Received: from mx1.redhat.com ([209.132.183.28]:4742 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755389Ab2GQVZk (ORCPT ); Tue, 17 Jul 2012 17:25:40 -0400 Content-Disposition: inline In-Reply-To: <20120716203344.1752.14606.stgit@bling.home> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Jul 16, 2012 at 02:33:47PM -0600, Alex Williamson wrote: > @@ -96,6 +183,9 @@ irqfd_shutdown(struct work_struct *work) > * It is now safe to release the object's resources > */ > eventfd_ctx_put(irqfd->eventfd); > + > + _irq_source_put(irqfd->source); > + > kfree(irqfd); > } > Hang on, this is a bug I think. This is done asynchronously. So this means that I can assign MAX number of irqfds, then close one, and now assign will fail because deassign did not get freed. Maybe we can solve this by flushing wq before assign? Looks a bit fragile but may be enough - need to document well. -- MST