Documentation/ABI/testing/sysfs-block-bcache

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-block-bcache

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-block-bcache
Extension
[no extension]
Size
5641 bytes
Lines
150
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

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>

Annotation

Implementation Notes