From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757667AbYGJVwT (ORCPT ); Thu, 10 Jul 2008 17:52:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752366AbYGJVwF (ORCPT ); Thu, 10 Jul 2008 17:52:05 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:56561 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752173AbYGJVwD (ORCPT ); Thu, 10 Jul 2008 17:52:03 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: "Thomas Gleixner Gleixner" CC: Ingo Molnar , Date: Thu, 10 Jul 2008 14:48:54 -0700 Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SA-Exim-Connect-IP: 24.130.11.59 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;"Thomas Gleixner Gleixner" X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% * [score: 0.4975] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 XM_SPF_Neutral SPF-Neutral Subject: [PATCH] Enable polling for disabled screaming irqs X-SA-Exim-Version: 4.2 (built Thu, 03 Mar 2005 10:44:12 +0100) X-SA-Exim-Scanned: Yes (on mgr1.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When we disable a screaming irq we never see it again. If the irq line is shared or if the driver half works this is a real pain. So periodically poll the handlers for screaming interrupts. I use a timer instead of the classic irq poll technique of working off the timer interrupt because when we use the local apic timers note_interrupt is never called (bug?). Further on a system with dynamic ticks the timer interrupt might not even fire unless there is a timer telling it it needs to. I forced this case on my test system with an e1000 nic and my ssh session remained responsive despite the interrupt handler only being called every 10th of a second. Signed-off-by: Eric W. Biederman --- kernel/irq/spurious.c | 147 ++++++++++++++++++++++++++++++------------------ 1 files changed, 92 insertions(+), 55 deletions(-) diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index c66d3f1..3d97eba 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -12,83 +12,118 @@ #include #include #include +#include static int irqfixup __read_mostly; +#define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) +static void poll_spurious_irqs(unsigned long dummy); +static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); + /* * Recovery handler for misrouted interrupts. */ -static int misrouted_irq(int irq) +static int try_one_irq(int irq, struct irq_desc *desc) { - int i; + struct irqaction *action; int ok = 0; int work = 0; /* Did we do work for a real IRQ */ - for (i = 1; i < NR_IRQS; i++) { - struct irq_desc *desc = irq_desc + i; - struct irqaction *action; - - if (i == irq) /* Already tried */ - continue; - - spin_lock(&desc->lock); - /* Already running on another processor */ - if (desc->status & IRQ_INPROGRESS) { - /* - * Already running: If it is shared get the other - * CPU to go looking for our mystery interrupt too - */ - if (desc->action && (desc->action->flags & IRQF_SHARED)) - desc->status |= IRQ_PENDING; - spin_unlock(&desc->lock); - continue; - } - /* Honour the normal IRQ locking */ - desc->status |= IRQ_INPROGRESS; - action = desc->action; + spin_lock(&desc->lock); + /* Already running on another processor */ + if (desc->status & IRQ_INPROGRESS) { + /* + * Already running: If it is shared get the other + * CPU to go looking for our mystery interrupt too + */ + if (desc->action && (desc->action->flags & IRQF_SHARED)) + desc->status |= IRQ_PENDING; spin_unlock(&desc->lock); + return ok; + } + /* Honour the normal IRQ locking */ + desc->status |= IRQ_INPROGRESS; + action = desc->action; + spin_unlock(&desc->lock); - while (action) { - /* Only shared IRQ handlers are safe to call */ - if (action->flags & IRQF_SHARED) { - if (action->handler(i, action->dev_id) == - IRQ_HANDLED) - ok = 1; - } - action = action->next; + while (action) { + /* Only shared IRQ handlers are safe to call */ + if (action->flags & IRQF_SHARED) { + if (action->handler(irq, action->dev_id) == + IRQ_HANDLED) + ok = 1; } - local_irq_disable(); - /* Now clean up the flags */ - spin_lock(&desc->lock); - action = desc->action; + action = action->next; + } + local_irq_disable(); + /* Now clean up the flags */ + spin_lock(&desc->lock); + action = desc->action; + /* + * While we were looking for a fixup someone queued a real + * IRQ clashing with our walk: + */ + while ((desc->status & IRQ_PENDING) && action) { /* - * While we were looking for a fixup someone queued a real - * IRQ clashing with our walk: - */ - while ((desc->status & IRQ_PENDING) && action) { - /* - * Perform real IRQ processing for the IRQ we deferred - */ - work = 1; - spin_unlock(&desc->lock); - handle_IRQ_event(i, action); - spin_lock(&desc->lock); - desc->status &= ~IRQ_PENDING; - } - desc->status &= ~IRQ_INPROGRESS; - /* - * If we did actual work for the real IRQ line we must let the - * IRQ controller clean up too + * Perform real IRQ processing for the IRQ we deferred */ - if (work && desc->chip && desc->chip->end) - desc->chip->end(i); + work = 1; spin_unlock(&desc->lock); + handle_IRQ_event(irq, action); + spin_lock(&desc->lock); + desc->status &= ~IRQ_PENDING; + } + desc->status &= ~IRQ_INPROGRESS; + /* + * If we did actual work for the real IRQ line we must let the + * IRQ controller clean up too + */ + if (work && desc->chip && desc->chip->end) + desc->chip->end(irq); + spin_unlock(&desc->lock); + + return ok; + +} + +static int misrouted_irq(int irq) +{ + int i; + int ok = 0; + + for (i = 1; i < NR_IRQS; i++) { + struct irq_desc *desc = irq_desc + i; + + if (i == irq) /* Already tried */ + continue; + + if (try_one_irq(i, desc)) + ok = 1; } /* So the caller can adjust the irq error counts */ return ok; } +static void poll_spurious_irqs(unsigned long dummy) +{ + int i; + for (i = 1; i < NR_IRQS; i++) { + struct irq_desc *desc = irq_desc + i; + unsigned int status; + + /* Racy but it doesn't matter */ + status = desc->status; + barrier(); + if (!(status & IRQ_SPURIOUS_DISABLED)) + continue; + + try_one_irq(i, desc); + } + + mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); +} + /* * If 99,900 of the previous 100,000 interrupts have not been handled * then assume that the IRQ is stuck in some manner. Drop a diagnostic @@ -212,6 +247,8 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED; desc->depth++; desc->chip->disable(irq); + + mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } desc->irqs_unhandled = 0; } -- 1.5.3.rc6.17.g1911