genirq: Expose irq_desc->node in proc/irq
Expose irq_desc->node as /proc/irq/*/node.
This file provides device hardware locality information for apps
desiring to include hardware locality in irq mapping decisions.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index a4f30fa..6507d2a 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -566,6 +566,10 @@
IRQs which have not yet been allocated/activated, and hence which lack a
/proc/irq/[0-9]* directory.
+The node file on an SMP system shows the node to which the device using the IRQ
+reports itself as being attached. This hardware locality information does not
+include information about any possible driver locality preference.
+
prof_cpu_mask specifies which CPUs are to be profiled by the system wide
profiler. Default value is ffffffff (all cpus).
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 6f50ecc..e346e08 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -146,6 +146,26 @@
.release = single_release,
.write = default_affinity_write,
};
+
+static int irq_node_proc_show(struct seq_file *m, void *v)
+{
+ struct irq_desc *desc = irq_to_desc((long) m->private);
+
+ seq_printf(m, "%d\n", desc->node);
+ return 0;
+}
+
+static int irq_node_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, irq_node_proc_show, PDE(inode)->data);
+}
+
+static const struct file_operations irq_node_proc_fops = {
+ .open = irq_node_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
#endif
static int irq_spurious_proc_show(struct seq_file *m, void *v)
@@ -230,6 +250,9 @@
/* create /proc/irq/<irq>/smp_affinity */
proc_create_data("smp_affinity", 0600, desc->dir,
&irq_affinity_proc_fops, (void *)(long)irq);
+
+ proc_create_data("node", 0444, desc->dir,
+ &irq_node_proc_fops, (void *)(long)irq);
#endif
proc_create_data("spurious", 0444, desc->dir,