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| author | Jens Axboe <jens.axboe@oracle.com> | 2009-01-23 10:54:44 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2009-01-30 12:34:38 +0100 |
| commit | bc58ba9468d94d62c56ab9b47173583ec140b165 (patch) | |
| tree | e31bee7a5001efdd40ed568151d5fdfa8b1a746a /include/linux/blkdev.h | |
| parent | 7598909e3ee2a08726276d6415b69dadb52d0d76 (diff) | |
| download | lwn-bc58ba9468d94d62c56ab9b47173583ec140b165.tar.gz lwn-bc58ba9468d94d62c56ab9b47173583ec140b165.zip | |
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.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 75426e4b8cdf..d08c4b8219a6 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) |