From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] IRQ fix incorrect logic in __clear_irq_vector (v2) Date: Fri, 12 Aug 2011 16:21:06 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andrew Cooper , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 12/08/2011 14:54, "Andrew Cooper" wrote: > In the old code, tmp_mask is the cpu_and of cfg->cpu_mask and > cpu_online_map. However, in the usual case of moving an IRQ from one > PCPU to another because the scheduler decides its a good idea, > cfg->cpu_mask and cfg->old_cpu_mask do not intersect. This causes the > old cpu vector_irq table to keep the irq reference when it shouldn't. > > This leads to a resource leak if a domain is shut down wile an irq has > a move pending, which results in Xen's create_irq() eventually failing > with -ENOSPC when all vector_irq tables are full of stale references. > > v2: reuse tmp_mask to take account of online cpus Nasty bug, nice fix! The extra field in irq_cfg sounds plausible to me -- I don't mind adding it if it's a nice cleanup. Thanks, Keir > Signed-off-by: Andrew Cooper > > diff -r 1f08b380d438 -r bd106cc2aa65 xen/arch/x86/irq.c > --- a/xen/arch/x86/irq.c Wed Aug 10 14:43:34 2011 +0100 > +++ b/xen/arch/x86/irq.c Fri Aug 12 14:54:11 2011 +0100 > @@ -216,6 +216,7 @@ static void __clear_irq_vector(int irq) > > if (likely(!cfg->move_in_progress)) > return; > + cpus_and(tmp_mask, cfg->old_cpu_mask, cpu_online_map); > for_each_cpu_mask(cpu, tmp_mask) { > for (vector = FIRST_DYNAMIC_VECTOR; vector <= LAST_DYNAMIC_VECTOR; > vector++) { > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel