18c2ecf20Sopenharmony_ci# SPDX-License-Identifier: GPL-2.0-only 28c2ecf20Sopenharmony_ci 38c2ecf20Sopenharmony_ciconfig FSCACHE 48c2ecf20Sopenharmony_ci tristate "General filesystem local caching manager" 58c2ecf20Sopenharmony_ci help 68c2ecf20Sopenharmony_ci This option enables a generic filesystem caching manager that can be 78c2ecf20Sopenharmony_ci used by various network and other filesystems to cache data locally. 88c2ecf20Sopenharmony_ci Different sorts of caches can be plugged in, depending on the 98c2ecf20Sopenharmony_ci resources available. 108c2ecf20Sopenharmony_ci 118c2ecf20Sopenharmony_ci See Documentation/filesystems/caching/fscache.rst for more information. 128c2ecf20Sopenharmony_ci 138c2ecf20Sopenharmony_ciconfig FSCACHE_STATS 148c2ecf20Sopenharmony_ci bool "Gather statistical information on local caching" 158c2ecf20Sopenharmony_ci depends on FSCACHE && PROC_FS 168c2ecf20Sopenharmony_ci help 178c2ecf20Sopenharmony_ci This option causes statistical information to be gathered on local 188c2ecf20Sopenharmony_ci caching and exported through file: 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci /proc/fs/fscache/stats 218c2ecf20Sopenharmony_ci 228c2ecf20Sopenharmony_ci The gathering of statistics adds a certain amount of overhead to 238c2ecf20Sopenharmony_ci execution as there are a quite a few stats gathered, and on a 248c2ecf20Sopenharmony_ci multi-CPU system these may be on cachelines that keep bouncing 258c2ecf20Sopenharmony_ci between CPUs. On the other hand, the stats are very useful for 268c2ecf20Sopenharmony_ci debugging purposes. Saying 'Y' here is recommended. 278c2ecf20Sopenharmony_ci 288c2ecf20Sopenharmony_ci See Documentation/filesystems/caching/fscache.rst for more information. 298c2ecf20Sopenharmony_ci 308c2ecf20Sopenharmony_ciconfig FSCACHE_HISTOGRAM 318c2ecf20Sopenharmony_ci bool "Gather latency information on local caching" 328c2ecf20Sopenharmony_ci depends on FSCACHE && PROC_FS 338c2ecf20Sopenharmony_ci help 348c2ecf20Sopenharmony_ci This option causes latency information to be gathered on local 358c2ecf20Sopenharmony_ci caching and exported through file: 368c2ecf20Sopenharmony_ci 378c2ecf20Sopenharmony_ci /proc/fs/fscache/histogram 388c2ecf20Sopenharmony_ci 398c2ecf20Sopenharmony_ci The generation of this histogram adds a certain amount of overhead to 408c2ecf20Sopenharmony_ci execution as there are a number of points at which data is gathered, 418c2ecf20Sopenharmony_ci and on a multi-CPU system these may be on cachelines that keep 428c2ecf20Sopenharmony_ci bouncing between CPUs. On the other hand, the histogram may be 438c2ecf20Sopenharmony_ci useful for debugging purposes. Saying 'N' here is recommended. 448c2ecf20Sopenharmony_ci 458c2ecf20Sopenharmony_ci See Documentation/filesystems/caching/fscache.rst for more information. 468c2ecf20Sopenharmony_ci 478c2ecf20Sopenharmony_ciconfig FSCACHE_DEBUG 488c2ecf20Sopenharmony_ci bool "Debug FS-Cache" 498c2ecf20Sopenharmony_ci depends on FSCACHE 508c2ecf20Sopenharmony_ci help 518c2ecf20Sopenharmony_ci This permits debugging to be dynamically enabled in the local caching 528c2ecf20Sopenharmony_ci management module. If this is set, the debugging output may be 538c2ecf20Sopenharmony_ci enabled by setting bits in /sys/modules/fscache/parameter/debug. 548c2ecf20Sopenharmony_ci 558c2ecf20Sopenharmony_ci See Documentation/filesystems/caching/fscache.rst for more information. 568c2ecf20Sopenharmony_ci 578c2ecf20Sopenharmony_ciconfig FSCACHE_OBJECT_LIST 588c2ecf20Sopenharmony_ci bool "Maintain global object list for debugging purposes" 598c2ecf20Sopenharmony_ci depends on FSCACHE && PROC_FS 608c2ecf20Sopenharmony_ci help 618c2ecf20Sopenharmony_ci Maintain a global list of active fscache objects that can be 628c2ecf20Sopenharmony_ci retrieved through /proc/fs/fscache/objects for debugging purposes 63