linux/fs/fscache/Kconfig
David Howells 4fbf4291aa FS-Cache: Allow the current state of all objects to be dumped
Allow the current state of all fscache objects to be dumped by doing:

	cat /proc/fs/fscache/objects

By default, all objects and all fields will be shown.  This can be restricted
by adding a suitable key to one of the caller's keyrings (such as the session
keyring):

	keyctl add user fscache:objlist "<restrictions>" @s

The <restrictions> are:

	K	Show hexdump of object key (don't show if not given)
	A	Show hexdump of object aux data (don't show if not given)

And paired restrictions:

	C	Show objects that have a cookie
	c	Show objects that don't have a cookie
	B	Show objects that are busy
	b	Show objects that aren't busy
	W	Show objects that have pending writes
	w	Show objects that don't have pending writes
	R	Show objects that have outstanding reads
	r	Show objects that don't have outstanding reads
	S	Show objects that have slow work queued
	s	Show objects that don't have slow work queued

If neither side of a restriction pair is given, then both are implied.  For
example:

	keyctl add user fscache:objlist KB @s

shows objects that are busy, and lists their object keys, but does not dump
their auxiliary data.  It also implies "CcWwRrSs", but as 'B' is given, 'b' is
not implied.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:11:04 +00:00

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config FSCACHE
tristate "General filesystem local caching manager"
depends on EXPERIMENTAL
select SLOW_WORK
help
This option enables a generic filesystem caching manager that can be
used by various network and other filesystems to cache data locally.
Different sorts of caches can be plugged in, depending on the
resources available.
See Documentation/filesystems/caching/fscache.txt for more information.
config FSCACHE_STATS
bool "Gather statistical information on local caching"
depends on FSCACHE && PROC_FS
help
This option causes statistical information to be gathered on local
caching and exported through file:
/proc/fs/fscache/stats
The gathering of statistics adds a certain amount of overhead to
execution as there are a quite a few stats gathered, and on a
multi-CPU system these may be on cachelines that keep bouncing
between CPUs. On the other hand, the stats are very useful for
debugging purposes. Saying 'Y' here is recommended.
See Documentation/filesystems/caching/fscache.txt for more information.
config FSCACHE_HISTOGRAM
bool "Gather latency information on local caching"
depends on FSCACHE && PROC_FS
help
This option causes latency information to be gathered on local
caching and exported through file:
/proc/fs/fscache/histogram
The generation of this histogram adds a certain amount of overhead to
execution as there are a number of points at which data is gathered,
and on a multi-CPU system these may be on cachelines that keep
bouncing between CPUs. On the other hand, the histogram may be
useful for debugging purposes. Saying 'N' here is recommended.
See Documentation/filesystems/caching/fscache.txt for more information.
config FSCACHE_DEBUG
bool "Debug FS-Cache"
depends on FSCACHE
help
This permits debugging to be dynamically enabled in the local caching
management module. If this is set, the debugging output may be
enabled by setting bits in /sys/modules/fscache/parameter/debug.
See Documentation/filesystems/caching/fscache.txt for more information.
config FSCACHE_OBJECT_LIST
bool "Maintain global object list for debugging purposes"
depends on FSCACHE && PROC_FS
help
Maintain a global list of active fscache objects that can be
retrieved through /proc/fs/fscache/objects for debugging purposes