1*4882a593Smuzhiyun# SPDX-License-Identifier: GPL-2.0-only 2*4882a593Smuzhiyun 3*4882a593Smuzhiyunconfig CACHEFILES 4*4882a593Smuzhiyun tristate "Filesystem caching on files" 5*4882a593Smuzhiyun depends on FSCACHE && BLOCK 6*4882a593Smuzhiyun help 7*4882a593Smuzhiyun This permits use of a mounted filesystem as a cache for other 8*4882a593Smuzhiyun filesystems - primarily networking filesystems - thus allowing fast 9*4882a593Smuzhiyun local disk to enhance the speed of slower devices. 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun See Documentation/filesystems/caching/cachefiles.rst for more 12*4882a593Smuzhiyun information. 13*4882a593Smuzhiyun 14*4882a593Smuzhiyunconfig CACHEFILES_DEBUG 15*4882a593Smuzhiyun bool "Debug CacheFiles" 16*4882a593Smuzhiyun depends on CACHEFILES 17*4882a593Smuzhiyun help 18*4882a593Smuzhiyun This permits debugging to be dynamically enabled in the filesystem 19*4882a593Smuzhiyun caching on files module. If this is set, the debugging output may be 20*4882a593Smuzhiyun enabled by setting bits in /sys/modules/cachefiles/parameter/debug or 21*4882a593Smuzhiyun by including a debugging specifier in /etc/cachefilesd.conf. 22*4882a593Smuzhiyun 23*4882a593Smuzhiyunconfig CACHEFILES_HISTOGRAM 24*4882a593Smuzhiyun bool "Gather latency information on CacheFiles" 25*4882a593Smuzhiyun depends on CACHEFILES && PROC_FS 26*4882a593Smuzhiyun help 27*4882a593Smuzhiyun 28*4882a593Smuzhiyun This option causes latency information to be gathered on CacheFiles 29*4882a593Smuzhiyun operation and exported through file: 30*4882a593Smuzhiyun 31*4882a593Smuzhiyun /proc/fs/cachefiles/histogram 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun The generation of this histogram adds a certain amount of overhead to 34*4882a593Smuzhiyun execution as there are a number of points at which data is gathered, 35*4882a593Smuzhiyun and on a multi-CPU system these may be on cachelines that keep 36*4882a593Smuzhiyun bouncing between CPUs. On the other hand, the histogram may be 37*4882a593Smuzhiyun useful for debugging purposes. Saying 'N' here is recommended. 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun See Documentation/filesystems/caching/cachefiles.rst for more 40*4882a593Smuzhiyun information. 41