実行環境Debian sid amd64

$ lsb_release -dr
Description:    Debian GNU/Linux bullseye/sid
Release:        unstable
$ uname -r
5.8.0-2-amd64
$ cat /proc/cpuinfo | grep -m1 model\ name
model name      : Intel(R) Core(TM) i5-3320M CPU @ 2.60GHz
$ head -1 /proc/meminfo
MemTotal:       16068904 kB

環境を用意(Debianのkernel)

$ sudo apt build-dep linux
$ apt source linux
$ cd linux-5.8.10
$ cp /boot/config-5.8.0-2-amd64 ./.config

f2fsの圧縮オプションを有効に

$ make menuconfig
$ diff -u /boot/config-5.8.0-2-amd64 .config                       
--- /boot/config-5.8.0-2-amd64  2020-09-19 21:17:19.000000000 +0900                                
+++ .config     2020-09-29 00:36:11.634990009 +0900                                                
@@ -2,10 +2,10 @@                                                                                  
 # Automatically generated file; DO NOT EDIT.                                                      
 # Linux/x86 5.8.10 Kernel Configuration                                                           
 #                                                                                                 
-CONFIG_CC_VERSION_TEXT="gcc-10 (Debian 10.2.0-9) 10.2.0"                                          
+CONFIG_CC_VERSION_TEXT="gcc (Debian 10.2.0-11) 10.2.0"                                            
 CONFIG_CC_IS_GCC=y                                                                                
 CONFIG_GCC_VERSION=100200                                                                         
-CONFIG_LD_VERSION=235000000                                                                       
+CONFIG_LD_VERSION=235010000                                                                       
 CONFIG_CLANG_VERSION=0                                                                            
 CONFIG_CC_CAN_LINK=y                                                                              
 CONFIG_CC_CAN_LINK_STATIC=y                                                                       
@@ -8474,7 +8474,11 @@                                                                             
 # CONFIG_F2FS_CHECK_FS is not set                                                                 
 # CONFIG_F2FS_IO_TRACE is not set                                                                 
 # CONFIG_F2FS_FAULT_INJECTION is not set                                                          
-# CONFIG_F2FS_FS_COMPRESSION is not set                                                           
+CONFIG_F2FS_FS_COMPRESSION=y                                                                      
+CONFIG_F2FS_FS_LZO=y                                                                              
+CONFIG_F2FS_FS_LZ4=y                                                                              
+CONFIG_F2FS_FS_ZSTD=y                                                                             
+CONFIG_F2FS_FS_LZORLE=y                                                                           
 # CONFIG_ZONEFS_FS is not set                                                                     
 CONFIG_FS_DAX=y                                                                                   
 CONFIG_FS_DAX_PMD=y                                                                               
@@ -9185,11 +9189,11 @@                                                                            
 CONFIG_ZLIB_DEFLATE=y                                                                             
 CONFIG_LZO_COMPRESS=y                                                                             
 CONFIG_LZO_DECOMPRESS=y                                                                           
-CONFIG_LZ4_COMPRESS=m                                                                             
+CONFIG_LZ4_COMPRESS=y                                                                             
 CONFIG_LZ4HC_COMPRESS=m                                                                           
 CONFIG_LZ4_DECOMPRESS=y                                                                           
-CONFIG_ZSTD_COMPRESS=m                                                                            
-CONFIG_ZSTD_DECOMPRESS=m                                                                          
+CONFIG_ZSTD_COMPRESS=y                                                                            
+CONFIG_ZSTD_DECOMPRESS=y                                                                          
 CONFIG_XZ_DEC=y                                                                                   
 CONFIG_XZ_DEC_X86=y                                                                               
 # CONFIG_XZ_DEC_POWERPC is not set

build

$ time make -j`nproc` bindeb-pkg LOCALVERSION=-fsf2
  :
dpkg-deb: building package 'linux-libc-dev' in '../linux-libc-dev_5.8.10-fsf2-1_amd64.deb'.
dpkg-deb: building package 'linux-image-5.8.10-fsf2' in '../linux-image-5.8.10-fsf2_5.8.10-fsf2-1_amd64.deb'.
dpkg-deb: building package 'linux-image-5.8.10-fsf2-dbg' in '../linux-image-5.8.10-fsf2-dbg_5.8.10-fsf2-1_amd64.deb'.
 dpkg-genbuildinfo --build=binary
 dpkg-genchanges --build=binary >../linux-5.8.10-fsf2_5.8.10-fsf2-1_amd64.changes
dpkg-genchanges: info: binary-only upload (no source code included)
 dpkg-source --after-build .
dpkg-buildpackage: info: binary-only upload (no source included)

real    213m16.364s
user    504m6.231s
sys     42m41.517s

出来上がったdebをインストールして再起動

$ ls -ltra ../linux-*5.8.10*.deb
-rw-r--r-- 1 matoken matoken   7908544 Sep 29 04:08 ../linux-headers-5.8.10-fsf2_5.8.10-fsf2-1_amd64.deb
-rw-r--r-- 1 matoken matoken   1111488 Sep 29 04:08 ../linux-libc-dev_5.8.10-fsf2-1_amd64.deb
-rw-r--r-- 1 matoken matoken  50507732 Sep 29 04:11 ../linux-image-5.8.10-fsf2_5.8.10-fsf2-1_amd64.deb
-rw-r--r-- 1 matoken matoken 635572404 Sep 29 04:41 ../linux-image-5.8.10-fsf2-dbg_5.8.10-fsf2-1_amd64.deb
$ sudo apt install ../linux-image-5.8.10-fsf2_5.8.10-fsf2-1_amd64.deb
$ reboot

対象kernelを選択して起動

$ uname -r
5.8.10-fsf2