diff options
Diffstat (limited to 'Documentation/block')
| -rw-r--r-- | Documentation/block/bfq-iosched.txt | 7 | ||||
| -rw-r--r-- | Documentation/block/biovecs.txt | 25 | ||||
| -rw-r--r-- | Documentation/block/null_blk.txt | 3 | ||||
| -rw-r--r-- | Documentation/block/queue-sysfs.txt | 7 |
4 files changed, 41 insertions, 1 deletions
diff --git a/Documentation/block/bfq-iosched.txt b/Documentation/block/bfq-iosched.txt index 8d8d8f06cab2..98a8dd5ee385 100644 --- a/Documentation/block/bfq-iosched.txt +++ b/Documentation/block/bfq-iosched.txt @@ -357,6 +357,13 @@ video playing/streaming, a very low drop rate may be more important than maximum throughput. In these cases, consider setting the strict_guarantees parameter. +slice_idle_us +------------- + +Controls the same tuning parameter as slice_idle, but in microseconds. +Either tunable can be used to set idling behavior. Afterwards, the +other tunable will reflect the newly set value in sysfs. + strict_guarantees ----------------- diff --git a/Documentation/block/biovecs.txt b/Documentation/block/biovecs.txt index 25689584e6e0..ce6eccaf5df7 100644 --- a/Documentation/block/biovecs.txt +++ b/Documentation/block/biovecs.txt @@ -117,3 +117,28 @@ Other implications: size limitations and the limitations of the underlying devices. Thus there's no need to define ->merge_bvec_fn() callbacks for individual block drivers. + +Usage of helpers: +================= + +* The following helpers whose names have the suffix of "_all" can only be used +on non-BIO_CLONED bio. They are usually used by filesystem code. Drivers +shouldn't use them because the bio may have been split before it reached the +driver. + + bio_for_each_segment_all() + bio_first_bvec_all() + bio_first_page_all() + bio_last_bvec_all() + +* The following helpers iterate over single-page segment. The passed 'struct +bio_vec' will contain a single-page IO vector during the iteration + + bio_for_each_segment() + bio_for_each_segment_all() + +* The following helpers iterate over multi-page bvec. The passed 'struct +bio_vec' will contain a multi-page IO vector during the iteration + + bio_for_each_bvec() + rq_for_each_bvec() diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt index ea2dafe49ae8..4cad1024fff7 100644 --- a/Documentation/block/null_blk.txt +++ b/Documentation/block/null_blk.txt @@ -88,7 +88,8 @@ shared_tags=[0/1]: Default: 0 zoned=[0/1]: Default: 0 0: Block device is exposed as a random-access block device. - 1: Block device is exposed as a host-managed zoned block device. + 1: Block device is exposed as a host-managed zoned block device. Requires + CONFIG_BLK_DEV_ZONED. zone_size=[MB]: Default: 256 Per zone size when exposed as a zoned block device. Must be a power of two. diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index 39e286d7afc9..83b457e24bba 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -67,6 +67,13 @@ If set to a value larger than 0, the kernel will put the process issuing IO to sleep for this amount of microseconds before entering classic polling. +io_timeout (RW) +--------------- +io_timeout is the request timeout in milliseconds. If a request does not +complete in this time then the block driver timeout handler is invoked. +That timeout handler can decide to retry the request, to fail it or to start +a device recovery strategy. + iostats (RW) ------------- This file is used to control (on/off) the iostats accounting of the |