Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932857Ab0HLAHb (ORCPT ); Wed, 11 Aug 2010 20:07:31 -0400 Received: from kroah.org ([198.145.64.141]:60363 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932820Ab0HLAEm (ORCPT ); Wed, 11 Aug 2010 20:04:42 -0400 X-Mailbox-Line: From gregkh@clark.site Wed Aug 11 17:01:27 2010 Message-Id: <20100812000127.764225887@clark.site> User-Agent: quilt/0.48-11.2 Date: Wed, 11 Aug 2010 17:01:04 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ian Campbell , Jeremy Fitzhardinge , xen-devel@lists.xensource.com, Thomas Gleixner Subject: [49/54] xen: Do not suspend IPI IRQs. In-Reply-To: <20100812000249.GA30948@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1694 Lines: 48 2.6.34-stable review patch. If anyone has any objections, please let us know. ------------------ From: Ian Campbell commit 4877c737283813bdb4bebfa3168c1585f6e3a8ca upstream. In general the semantics of IPIs are that they are are expected to continue functioning after dpm_suspend_noirq(). Specifically I have seen a deadlock between the callfunc IPI and the stop machine used by xen's do_suspend() routine. If one CPU has already called dpm_suspend_noirq() then there is a window where it can be sent a callfunc IPI before all the other CPUs have entered stop_cpu(). If this happens then the first CPU ends up spinning in stop_cpu() waiting for the other to rendezvous in state STOPMACHINE_PREPARE while the other is spinning in csd_lock_wait(). Signed-off-by: Ian Campbell Cc: Jeremy Fitzhardinge Cc: xen-devel@lists.xensource.com LKML-Reference: <1280398595-29708-4-git-send-email-ian.campbell@citrix.com> Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- drivers/xen/events.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -536,6 +536,7 @@ int bind_ipi_to_irqhandler(enum ipi_vect if (irq < 0) return irq; + irqflags |= IRQF_NO_SUSPEND; retval = request_irq(irq, handler, irqflags, devname, dev_id); if (retval != 0) { unbind_from_irq(irq); -- 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/