block: add support for IO CPU affinity

[linux-2.6-omap-h63xx.git] / block / blk-sysfs.c

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index b9a6ed1666494abac09c69db8bc3eecea4728c5f..21e275d7eed9444ab876834db2345eb78f4ae183 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -156,6 +156,30 @@ static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
        return ret;
 }
 
+static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
+{
+       unsigned int set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
+
+       return queue_var_show(set != 0, page);
+}
+
+static ssize_t
+queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
+{
+       ssize_t ret = -EINVAL;
+#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
+       unsigned long val;
+
+       ret = queue_var_store(&val, page, count);
+       spin_lock_irq(q->queue_lock);
+       if (val)
+               queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
+       else
+               queue_flag_clear(QUEUE_FLAG_SAME_COMP,  q);
+       spin_unlock_irq(q->queue_lock);
+#endif
+       return ret;
+}
 
 static struct queue_sysfs_entry queue_requests_entry = {
        .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
@@ -197,6 +221,12 @@ static struct queue_sysfs_entry queue_nomerges_entry = {
        .store = queue_nomerges_store,
 };
 
+static struct queue_sysfs_entry queue_rq_affinity_entry = {
+       .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
+       .show = queue_rq_affinity_show,
+       .store = queue_rq_affinity_store,
+};
+
 static struct attribute *default_attrs[] = {
        &queue_requests_entry.attr,
        &queue_ra_entry.attr,
@@ -205,6 +235,7 @@ static struct attribute *default_attrs[] = {
        &queue_iosched_entry.attr,
        &queue_hw_sector_size_entry.attr,
        &queue_nomerges_entry.attr,
+       &queue_rq_affinity_entry.attr,
        NULL,
 };