Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757060Ab0G2LcB (ORCPT ); Thu, 29 Jul 2010 07:32:01 -0400 Received: from hera.kernel.org ([140.211.167.34]:44785 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755840Ab0G2Lb7 (ORCPT ); Thu, 29 Jul 2010 07:31:59 -0400 Date: Thu, 29 Jul 2010 11:31:44 GMT From: tip-bot for Ian Campbell Cc: linux-kernel@vger.kernel.org, jeremy@goop.org, hpa@zytor.com, mingo@redhat.com, ian.campbell@citrix.com, tglx@linutronix.de Reply-To: mingo@redhat.com, hpa@zytor.com, jeremy@goop.org, linux-kernel@vger.kernel.org, ian.campbell@citrix.com, tglx@linutronix.de In-Reply-To: <1280398595-29708-4-git-send-email-ian.campbell@citrix.com> References: <1280398595-29708-4-git-send-email-ian.campbell@citrix.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:irq/core] xen: Do not suspend IPI IRQs. Message-ID: Git-Commit-ID: 4877c737283813bdb4bebfa3168c1585f6e3a8ca X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 29 Jul 2010 11:31:44 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1899 Lines: 47 Commit-ID: 4877c737283813bdb4bebfa3168c1585f6e3a8ca Gitweb: http://git.kernel.org/tip/4877c737283813bdb4bebfa3168c1585f6e3a8ca Author: Ian Campbell AuthorDate: Thu, 29 Jul 2010 11:16:35 +0100 Committer: Thomas Gleixner CommitDate: Thu, 29 Jul 2010 13:24:58 +0200 xen: Do not suspend IPI IRQs. 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 --- drivers/xen/events.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/xen/events.c b/drivers/xen/events.c index db8f506..28f133a 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -536,6 +536,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi, 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/