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authorAshok Raj <ashok.raj@intel.com>2005-09-06 15:16:15 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-07 16:57:15 -0700
commit54d5d42404e7705cf3804593189e963350d470e5 (patch)
tree7cf8a7fce163b19672193d8cf4ef6a7f6c131d9e /kernel
parentf63ed39c578a2a2d067356a85ce7c28a7c795d8a (diff)
downloadlinux-54d5d42404e7705cf3804593189e963350d470e5.tar.bz2
[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 <ashok.raj@intel.com> Acked-by: Zwane Mwaikambo <zwane@holomorphy.com> Grudgingly-acked-by: Andi Kleen <ak@muc.de> Signed-off-by: Coywolf Qi Hunt <coywolf@lovecn.org> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/irq/manage.c4
-rw-r--r--kernel/irq/proc.c14
2 files changed, 16 insertions, 2 deletions
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)