summaryrefslogtreecommitdiff
path: root/Documentation/ABI
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2011-05-25 09:14:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-25 09:14:07 -0700
commit798ce8f1cca29dcc3f4b55947f611f4ffb32ac2b (patch)
tree15fba84ba4b930397c29fe562504f66211365699 /Documentation/ABI
parent22e12bbc9bc38c6d0bd541d061a0f547596fc19d (diff)
parent1547010e6e15a3f44f49381246421a1e19de526e (diff)
Merge branch 'for-2.6.40/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.40/core' of git://git.kernel.dk/linux-2.6-block: (40 commits) cfq-iosched: free cic_index if cfqd allocation fails cfq-iosched: remove unused 'group_changed' in cfq_service_tree_add() cfq-iosched: reduce bit operations in cfq_choose_req() cfq-iosched: algebraic simplification in cfq_prio_to_maxrq() blk-cgroup: Initialize ioc->cgroup_changed at ioc creation time block: move bd_set_size() above rescan_partitions() in __blkdev_get() block: call elv_bio_merged() when merged cfq-iosched: Make IO merge related stats per cpu cfq-iosched: Fix a memory leak of per cpu stats for root group backing-dev: Kill set but not used var in bdi_debug_stats_show() block: get rid of on-stack plugging debug checks blk-throttle: Make no throttling rule group processing lockless blk-cgroup: Make cgroup stat reset path blkg->lock free for dispatch stats blk-cgroup: Make 64bit per cpu stats safe on 32bit arch blk-throttle: Make dispatch stats per cpu blk-throttle: Free up a group only after one rcu grace period blk-throttle: Use helper function to add root throtl group to lists blk-throttle: Introduce a helper function to fill in device details blk-throttle: Dynamically allocate root group blk-cgroup: Allow sleeping while dynamically allocating a group ...
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/sysfs-block64
1 files changed, 64 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index 4873c759d535..c1eb41cb9876 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -142,3 +142,67 @@ Description:
with the previous I/O request are enabled. When set to 2,
all merge tries are disabled. The default value is 0 -
which enables all types of merge tries.
+
+What: /sys/block/<disk>/discard_alignment
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may
+ internally allocate space in units that are bigger than
+ the exported logical block size. The discard_alignment
+ parameter indicates how many bytes the beginning of the
+ device is offset from the internal allocation unit's
+ natural alignment.
+
+What: /sys/block/<disk>/<partition>/discard_alignment
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may
+ internally allocate space in units that are bigger than
+ the exported logical block size. The discard_alignment
+ parameter indicates how many bytes the beginning of the
+ partition is offset from the internal allocation unit's
+ natural alignment.
+
+What: /sys/block/<disk>/queue/discard_granularity
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may
+ internally allocate space using units that are bigger
+ than the logical block size. The discard_granularity
+ parameter indicates the size of the internal allocation
+ unit in bytes if reported by the device. Otherwise the
+ discard_granularity will be set to match the device's
+ physical block size. A discard_granularity of 0 means
+ that the device does not support discard functionality.
+
+What: /sys/block/<disk>/queue/discard_max_bytes
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may have
+ internal limits on the number of bytes that can be
+ trimmed or unmapped in a single operation. Some storage
+ protocols also have inherent limits on the number of
+ blocks that can be described in a single command. The
+ discard_max_bytes parameter is set by the device driver
+ to the maximum number of bytes that can be discarded in
+ a single operation. Discard requests issued to the
+ device must not exceed this limit. A discard_max_bytes
+ value of 0 means that the device does not support
+ discard functionality.
+
+What: /sys/block/<disk>/queue/discard_zeroes_data
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may return
+ stale or random data when a previously discarded block
+ is read back. This can cause problems if the filesystem
+ expects discarded blocks to be explicitly cleared. If a
+ device reports that it deterministically returns zeroes
+ when a discarded area is read the discard_zeroes_data
+ parameter will be set to one. Otherwise it will be 0 and
+ the result of reading a discarded area is undefined.