1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 2
3 config CACHEFILES 3 config CACHEFILES
4 tristate "Filesystem caching on files" 4 tristate "Filesystem caching on files"
5 depends on NETFS_SUPPORT && FSCACHE && !! 5 depends on FSCACHE && BLOCK
6 help 6 help
7 This permits use of a mounted filesy 7 This permits use of a mounted filesystem as a cache for other
8 filesystems - primarily networking f 8 filesystems - primarily networking filesystems - thus allowing fast
9 local disk to enhance the speed of s 9 local disk to enhance the speed of slower devices.
10 10
11 See Documentation/filesystems/cachin 11 See Documentation/filesystems/caching/cachefiles.rst for more
12 information. 12 information.
13 13
14 config CACHEFILES_DEBUG 14 config CACHEFILES_DEBUG
15 bool "Debug CacheFiles" 15 bool "Debug CacheFiles"
16 depends on CACHEFILES 16 depends on CACHEFILES
17 help 17 help
18 This permits debugging to be dynamic 18 This permits debugging to be dynamically enabled in the filesystem
19 caching on files module. If this is 19 caching on files module. If this is set, the debugging output may be
20 enabled by setting bits in /sys/modu 20 enabled by setting bits in /sys/modules/cachefiles/parameter/debug or
21 by including a debugging specifier i 21 by including a debugging specifier in /etc/cachefilesd.conf.
22 22
23 config CACHEFILES_ERROR_INJECTION !! 23 config CACHEFILES_HISTOGRAM
24 bool "Provide error injection for cach !! 24 bool "Gather latency information on CacheFiles"
25 depends on CACHEFILES && SYSCTL !! 25 depends on CACHEFILES && PROC_FS
26 help 26 help
27 This permits error injection to be e <<
28 cache is in service. <<
29 27
30 config CACHEFILES_ONDEMAND !! 28 This option causes latency information to be gathered on CacheFiles
31 bool "Support for on-demand read" !! 29 operation and exported through file:
32 depends on CACHEFILES !! 30
33 default n !! 31 /proc/fs/cachefiles/histogram
34 help <<
35 This permits userspace to enable the <<
36 In this mode, when a cache miss occu <<
37 the data lies with the cachefiles ba <<
38 and is delegated to userspace. <<
39 32
40 If unsure, say N. !! 33 The generation of this histogram adds a certain amount of overhead to
>> 34 execution as there are a number of points at which data is gathered,
>> 35 and on a multi-CPU system these may be on cachelines that keep
>> 36 bouncing between CPUs. On the other hand, the histogram may be
>> 37 useful for debugging purposes. Saying 'N' here is recommended.
>> 38
>> 39 See Documentation/filesystems/caching/cachefiles.rst for more
>> 40 information.
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