Shrinker Debugfs Shows Which Kernel Cache Holds Memory
Since Linux 6.0 the kernel has carried a debugfs interface that reports, for every registered shrinker, how many reclaimable objects that cache is currently holding, and lets you make one cache release objects on demand. It is gated behind CONFIG_SHRINKER_DEBUG, which carries no default value in any released kernel, so most boards do not have it even though their kernel version does. Every longterm series from 6.1 onwards contains the code; 5.15 and 5.10 do not. In Linux 7.0 the first column of…