From 54d5d42404e7705cf3804593189e963350d470e5 Mon Sep 17 00:00:00 2001 From: Ashok Raj Date: Tue, 6 Sep 2005 15:16:15 -0700 Subject: [PATCH] x86/x86_64: deferred handling of writes to /proc/irqxx/smp_affinity When handling writes to /proc/irq, current code is re-programming rte entries directly. This is not recommended and could potentially cause chipset's to lockup, or cause missing interrupts. CONFIG_IRQ_BALANCE does this correctly, where it re-programs only when the interrupt is pending. The same needs to be done for /proc/irq handling as well. Otherwise user space irq balancers are really not doing the right thing. - Changed pending_irq_balance_cpumask to pending_irq_migrate_cpumask for lack of a generic name. - added move_irq out of IRQ_BALANCE, and added this same to X86_64 - Added new proc handler for write, so we can do deferred write at irq handling time. - Display of /proc/irq/XX/smp_affinity used to display CPU_MASKALL, instead it now shows only active cpu masks, or exactly what was set. - Provided a common move_irq implementation, instead of duplicating when using generic irq framework. Tested on i386/x86_64 and ia64 with CONFIG_PCI_MSI turned on and off. Tested UP builds as well. MSI testing: tbd: I have cards, need to look for a x-over cable, although I did test an earlier version of this patch. Will test in a couple days. Signed-off-by: Ashok Raj Acked-by: Zwane Mwaikambo Grudgingly-acked-by: Andi Kleen Signed-off-by: Coywolf Qi Hunt Signed-off-by: Ashok Raj Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/irq/manage.c | 4 ++++ kernel/irq/proc.c | 14 ++++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index ac6700985705..1cfdb08ddf20 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -18,6 +18,10 @@ cpumask_t irq_affinity[NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL }; +#if defined (CONFIG_GENERIC_PENDING_IRQ) || defined (CONFIG_IRQBALANCE) +cpumask_t __cacheline_aligned pending_irq_cpumask[NR_IRQS]; +#endif + /** * synchronize_irq - wait for pending IRQ handlers (on other CPUs) * diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 85d08daa6600..f26e534c6585 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -19,12 +19,22 @@ static struct proc_dir_entry *root_irq_dir, *irq_dir[NR_IRQS]; */ static struct proc_dir_entry *smp_affinity_entry[NR_IRQS]; -void __attribute__((weak)) -proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) +#ifdef CONFIG_GENERIC_PENDING_IRQ +void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) +{ + /* + * Save these away for later use. Re-progam when the + * interrupt is pending + */ + set_pending_irq(irq, mask_val); +} +#else +void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) { irq_affinity[irq] = mask_val; irq_desc[irq].handler->set_affinity(irq, mask_val); } +#endif static int irq_affinity_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data) -- cgit v1.2.3-70-g09d2