CONFIG_ZLIB_DEFLATE (not configurable)

modulename: zlib_deflate.ko

configname: CONFIG_ZLIB_DEFLATE

Linux Kernel Configuration
└─>Library routines
└─>ZLIB_DEFLATE
In linux kernel since version 2.6.12  
source code:
is depended by
CONFIG_BTRFS_FS
CONFIG_LOGFS