Messages in this thread | | | From | "Iyer, Sundar" <> | Subject | RE: [PATCH v2] x86/irq: handle chained interrupts during IRQ migration | Date | Wed, 6 Jun 2012 17:52:21 +0000 |
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Hi Thomas,
Any comments on this version? Or do you suggest to add a new flag in the accessors and set it?
Thanks
>-----Original Message----- >From: Iyer, Sundar >Sent: Wednesday, May 30, 2012 2:59 PM >To: tglx@linutronix.de >Cc: linux-kernel@vger.kernel.org; lethal@linux-sh.org; arjan@linux.intel.com; Iyer, >Sundar; Monroy, German >Subject: [PATCH v2] x86/irq: handle chained interrupts during IRQ migration > >Chained interrupt handlers dont have an irqaction and hence are not handled during >migrating interrupts when some cores go offline. > >Handle this by introducing a irq_is_chained() check which is based on the the very least >NOREQUEST, NOPROBE, and NOTHREAD flags being set for such interrupts. >fixup_irq() can then handle such interrupts and not skip them over. > >Change-Id: I011de8bee98c1702a362deb06106845ca7bcad61 >Signed-off-by: Sundar Iyer <sundar.iyer@intel.com> >--- >v1: use accessors instead of new variables to identify chained irqs >v2: use a mask of NOREQUEST, NOPROBE, and NOTHREAD accessor flags as per >Paul M > > arch/x86/kernel/irq.c | 6 ++++-- > include/linux/irqdesc.h | 11 +++++++++++ > 2 files changed, 15 insertions(+), 2 deletions(-) > >diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 6c0802e..acd7949 100644 >--- a/arch/x86/kernel/irq.c >+++ b/arch/x86/kernel/irq.c >@@ -249,8 +249,10 @@ void fixup_irqs(void) > > data = irq_desc_get_irq_data(desc); > affinity = data->affinity; >- if (!irq_has_action(irq) || irqd_is_per_cpu(data) || >- cpumask_subset(affinity, cpu_online_mask)) { >+ /* include IRQs who have no action, but are chained */ >+ if ((!irq_has_action(irq) && irq_is_chained(irq)) || >+ irqd_is_per_cpu(data) || >+ cpumask_subset(affinity, cpu_online_mask)) { > raw_spin_unlock(&desc->lock); > continue; > } >diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 2d921b3..8d5eb42 >100644 >--- a/include/linux/irqdesc.h >+++ b/include/linux/irqdesc.h >@@ -120,6 +120,17 @@ static inline int irq_has_action(unsigned int irq) > return desc->action != NULL; > } > >+/* >+ * Test to see if the IRQ is chained; it would not be requested and >+hence >+ * very miinimum _IRQ_NOREQUEST, _IRQ_NOPROBE, _IRQ_NOTHREAD would be >+set */ static inline int irq_is_chained(unsigned int irq) { >+ struct irq_desc *desc = irq_to_desc(irq); >+ return !(desc->status_use_accessors & >+ (IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOTHREAD)); } >+ > /* caller has locked the irq_desc and both params are valid */ static inline void >__irq_set_handler_locked(unsigned int irq, > irq_flow_handler_t handler) >-- >1.7.1
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