R-Car/Debugging-kernel-options-causes-performance-down

Overview
A tree git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel.git has renesas_defconfig to ease development of drivers for Renesas ARM SoCs. The renesas_defconfig enables some debugging features so that this is convenient to detect issues of development drivers.

Location on v5.13-rc5: -> Kernel hacking -> Lock Debugging (spinlocks, mutexes, etc...)

[*] Lock debugging: prove locking correctness [ ]  Enable raw_spinlock - spinlock nesting checks [ ] Lock usage statistics -*- RT Mutex debugging, deadlock detection -*- Spinlock and rw-lock debugging: basic checks -*- Mutex debugging: basic checks -*- Wait/wound mutex debugging: Slowpath testing -*- RW Semaphore debugging: basic checks -*- Lock debugging: detect incorrect freeing of live locks

However, these lock debugging options is possible to cause CPU overhead so that benchmark score will be down.

bonnie++ score comparation
When we disable these lock debugging options on renesas-drivers-2021-06-08-v5.13-rc5, the score of bonnie++ is up.

debugging options are enabled
... Version 1.03e      --Sequential Output-- --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine       Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP buildroot   15624M 31011  97 62806  97 28923  48 37313  90 89776  66  4724  83 --Sequential Create-- Random Create -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP 16 5734  97 +++++ +++  4620  77  5844  97 +++++ +++  4953  84 buildroot,15624M,31011,97,62806,97,28923,48,37313,90,89776,66,4724.5,83,16,5734,97,+++++,+++,4620,77,5844,97,+++++,+++,4953,84
 * 1) mount -t ext4 /dev/mmcblk0 /mnt
 * 2) cd /mnt
 * 3) bonnie\+\+ -u root -d ./

debugging options are disabled
... Version 1.03e      --Sequential Output-- --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine       Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP buildroot   15656M 57092  98 138614  47 58098  23 54250  95 136543  35  8925  29 --Sequential Create-- Random Create -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP 16 29014 98 +++++ +++ 32079  97 29693  98 +++++ +++ 22302  76 buildroot,15656M,57092,98,138614,47,58098,23,54250,95,136543,35,8925.3,29,16,29014,98,+++++,+++,32079,97,29693,98,+++++,+++,22302,76
 * 1) mount -t ext4 /dev/mmcblk0 /mnt
 * 2) cd /mnt
 * 3) bonnie\+\+ -u root -d ./