--- /dev/null
+What: /sys/block/<disk>/bcache/unregister
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ A write to this file causes the backing device or cache to be
+ unregistered. If a backing device had dirty data in the cache,
+ writeback mode is automatically disabled and all dirty data is
+ flushed before the device is unregistered. Caches unregister
+ all associated backing devices before unregistering themselves.
+
+What: /sys/block/<disk>/bcache/clear_stats
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ Writing to this file resets all the statistics for the device.
+
+What: /sys/block/<disk>/bcache/cache
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For a backing device that has cache, a symlink to
+ the bcache/ dir of that cache.
+
+What: /sys/block/<disk>/bcache/cache_hits
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For backing devices: integer number of full cache hits,
+ counted per bio. A partial cache hit counts as a miss.
+
+What: /sys/block/<disk>/bcache/cache_misses
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For backing devices: integer number of cache misses.
+
+What: /sys/block/<disk>/bcache/cache_hit_ratio
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For backing devices: cache hits as a percentage.
+
+What: /sys/block/<disk>/bcache/sequential_cutoff
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For backing devices: Threshold past which sequential IO will
+ skip the cache. Read and written as bytes in human readable
+ units (i.e. echo 10M > sequntial_cutoff).
+
+What: /sys/block/<disk>/bcache/bypassed
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ Sum of all reads and writes that have bypassed the cache (due
+ to the sequential cutoff). Expressed as bytes in human
+ readable units.
+
+What: /sys/block/<disk>/bcache/writeback
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For backing devices: When on, writeback caching is enabled and
+ writes will be buffered in the cache. When off, caching is in
+ writethrough mode; reads and writes will be added to the
+ cache but no write buffering will take place.
+
+What: /sys/block/<disk>/bcache/writeback_running
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For backing devices: when off, dirty data will not be written
+ from the cache to the backing device. The cache will still be
+ used to buffer writes until it is mostly full, at which point
+ writes transparently revert to writethrough mode. Intended only
+ for benchmarking/testing.
+
+What: /sys/block/<disk>/bcache/writeback_delay
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For backing devices: In writeback mode, when dirty data is
+ written to the cache and the cache held no dirty data for that
+ backing device, writeback from cache to backing device starts
+ after this delay, expressed as an integer number of seconds.
+
+What: /sys/block/<disk>/bcache/writeback_percent
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For backing devices: If nonzero, writeback from cache to
+ backing device only takes place when more than this percentage
+ of the cache is used, allowing more write coalescing to take
+ place and reducing total number of writes sent to the backing
+ device. Integer between 0 and 40.
+
+What: /sys/block/<disk>/bcache/synchronous
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For a cache, a boolean that allows synchronous mode to be
+ switched on and off. In synchronous mode all writes are ordered
+ such that the cache can reliably recover from unclean shutdown;
+ if disabled bcache will not generally wait for writes to
+ complete but if the cache is not shut down cleanly all data
+ will be discarded from the cache. Should not be turned off with
+ writeback caching enabled.
+
+What: /sys/block/<disk>/bcache/discard
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For a cache, a boolean allowing discard/TRIM to be turned off
+ or back on if the device supports it.
+
+What: /sys/block/<disk>/bcache/bucket_size
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For a cache, bucket size in human readable units, as set at
+ cache creation time; should match the erase block size of the
+ SSD for optimal performance.
+
+What: /sys/block/<disk>/bcache/nbuckets
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For a cache, the number of usable buckets.
+
+What: /sys/block/<disk>/bcache/tree_depth
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For a cache, height of the btree excluding leaf nodes (i.e. a
+ one node tree will have a depth of 0).
+
+What: /sys/block/<disk>/bcache/btree_cache_size
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ Number of btree buckets/nodes that are currently cached in
+ memory; cache dynamically grows and shrinks in response to
+ memory pressure from the rest of the system.
+
+What: /sys/block/<disk>/bcache/written
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For a cache, total amount of data in human readable units
+ written to the cache, excluding all metadata.
+
+What: /sys/block/<disk>/bcache/btree_written
+Date: November 2010
+Contact: Kent Overstreet <kent.overstreet@gmail.com>
+Description:
+ For a cache, sum of all btree writes in human readable units.
Code Review / kvmfornfv.git / blobdiff