kernel/sched/rt.c:9:18: warning: 'max_rt_runtime' defined but not used

[kernel test robot <lkp@intel.com>]

Hi Baisong,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   58390c8ce1bddb6c623f62e7ed36383e7fa5c02f
commit: 28f152cd0926596e69d412467b11b6fe6fe4e864 sched/rt: fix build error when CONFIG_SYSCTL is disable
date:   1 year, 1 month ago
config: x86_64-buildonly-randconfig-r003-20230501 (https://download.01.org/0day-ci/archive/20230501/202305010616.hJPBk04Y-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=28f152cd0926596e69d412467b11b6fe6fe4e864
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 28f152cd0926596e69d412467b11b6fe6fe4e864
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/ kernel/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305010616.hJPBk04Y-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from kernel/sched/build_policy.c:43:
   kernel/sched/rt.c:309:6: warning: no previous prototype for 'unregister_rt_sched_group' [-Wmissing-prototypes]
     309 | void unregister_rt_sched_group(struct task_group *tg) { }
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c:311:6: warning: no previous prototype for 'free_rt_sched_group' [-Wmissing-prototypes]
     311 | void free_rt_sched_group(struct task_group *tg) { }
         |      ^~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c:313:5: warning: no previous prototype for 'alloc_rt_sched_group' [-Wmissing-prototypes]
     313 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
         |     ^~~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c:716:6: warning: no previous prototype for 'sched_rt_bandwidth_account' [-Wmissing-prototypes]
     716 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~
>> kernel/sched/rt.c:9:18: warning: 'max_rt_runtime' defined but not used [-Wunused-const-variable=]
       9 | static const u64 max_rt_runtime = MAX_BW;
         |                  ^~~~~~~~~~~~~~


vim +/max_rt_runtime +9 kernel/sched/rt.c

d505b8af58912a Huaixin Chang  2020-04-25  @9  static const u64 max_rt_runtime = MAX_BW;
ce0dbbbb30aee6 Clark Williams 2013-02-07  10  

:::::: The code at line 9 was first introduced by commit
:::::: d505b8af58912ae1e1a211fabc9995b19bd40828 sched: Defend cfs and rt bandwidth quota against overflow

:::::: TO: Huaixin Chang <changhuaixin@linux.alibaba.com>
:::::: CC: Peter Zijlstra <peterz@infradead.org>

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