block: add poll_considered statistic
In order to help determine the effectiveness of polling in a running
system it is usful to determine the ratio of how often the poll
function is called vs how often the completion is checked. For this
reason we add a poll_considered variable and add it to the sysfs entry
for io_poll.
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index e1544f0..7710f79 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -61,6 +61,7 @@
struct blk_mq_cpu_notifier cpu_notifier;
struct kobject kobj;
+ unsigned long poll_considered;
unsigned long poll_invoked;
unsigned long poll_success;
};