summaryrefslogtreecommitdiffstats
path: root/include/linux/blkdev.h
diff options
context:
space:
mode:
authorJens Axboe <jens.axboe@oracle.com>2009-01-23 10:54:44 +0100
committerJens Axboe <jens.axboe@oracle.com>2009-01-30 12:34:38 +0100
commitbc58ba9468d94d62c56ab9b47173583ec140b165 (patch)
treee31bee7a5001efdd40ed568151d5fdfa8b1a746a /include/linux/blkdev.h
parent7598909e3ee2a08726276d6415b69dadb52d0d76 (diff)
block: add sysfs file for controlling io stats accounting
This allows us to turn off disk stat accounting completely, for the cases where the 0.5-1% reduction in system time is important. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/blkdev.h')
-rw-r--r--include/linux/blkdev.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 75426e4b8cd..d08c4b8219a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -451,6 +451,11 @@ struct request_queue
#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
+#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
+
+#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
+ (1 << QUEUE_FLAG_CLUSTER) | \
+ 1 << QUEUE_FLAG_STACKABLE)
static inline int queue_is_locked(struct request_queue *q)
{
@@ -567,6 +572,7 @@ enum {
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
+#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
#define blk_queue_flushing(q) ((q)->ordseq)
#define blk_queue_stackable(q) \
test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)