[tip:sched/core 1/2] kernel/sched/core.c:223:1: warning: unused function 'rq_csd_init'

[kbuild test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core
head:   2a0a24ebb499c9d499eea948d3fc108f936e36d4
commit: 90b5363acd4739769c3f38c1aff16171bd133e8c [1/2] sched: Clean up scheduler_ipi()
config: mips-randconfig-r006-20200521 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 3393cc4cebf9969db94dc424b7a2b6195589c33b)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        git checkout 90b5363acd4739769c3f38c1aff16171bd133e8c
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

kernel/sched/core.c:4190:35: warning: no previous prototype for function 'schedule_user'
asmlinkage __visible void __sched schedule_user(void)
^
kernel/sched/core.c:4190:22: note: declare 'static' if the function is not intended to be used outside of this translation unit
asmlinkage __visible void __sched schedule_user(void)
^
static
>> kernel/sched/core.c:223:1: warning: unused function 'rq_csd_init'
rq_csd_init(struct rq call_single_data_t smp_call_func_t func)
^
kernel/sched/core.c:3744:20: warning: unused function 'sched_tick_start'
static inline void sched_tick_start(int cpu) { }
^
kernel/sched/core.c:3745:20: warning: unused function 'sched_tick_stop'
static inline void sched_tick_stop(int cpu) { }
^
fatal error: error in backend: Nested variants found in inline asm string: ' .set push
.set noat
.set push
.set arch=r4000
.if ( 0x00 ) != -1)) 0x00 ) != -1)) : ($( static struct ftrace_branch_data __attribute__((__aligned__(4))) __attribute__((__section__("_ftrace_branch"))) __if_trace = $( .func = __func__, .file = "arch/mips/include/asm/cmpxchg.h", .line = 163, $); 0x00 ) != -1)) : $))) ) && ( 0 ); .set push; .set mips64r2; .rept 1; sync 0x00; .endr; .set pop; .else; ; .endif
1: ll $0, $2 # __cmpxchg_asm
bne $0, ${3:z}, 2f
.set pop
move $$1, ${4:z}
.set arch=r4000
sc $$1, $1
beqz $$1, 1b
.set pop
2: .if ( 0x00 ) != -1)) 0x00 ) != -1)) : ($( static struct ftrace_branch_data __attribute__((__aligned__(4))) __attribute__((__section__("_ftrace_branch"))) __if_trace = $( .func = __func__, .file = "arch/mips/include/asm/cmpxchg.h", .line = 163, $); 0x00 ) != -1)) : $))) ) && ( 0 ); .set push; .set mips64r2; .rept 1; sync 0x00; .endr; .set pop; .else; ; .endif
'
clang-11: error: clang frontend command failed with exit code 70 (use -v to see invocation)
clang version 11.0.0 (git://gitmirror/llvm_project 3393cc4cebf9969db94dc424b7a2b6195589c33b)
Target: mipsel-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/cross/clang-3393cc4ceb/bin
clang-11: note: diagnostic msg:
Makefile arch include kernel null.dwo scripts source usr

vim +/rq_csd_init +223 kernel/sched/core.c

   221	
   222	static inline void
 > 223	rq_csd_init(struct rq *rq, call_single_data_t *csd, smp_call_func_t func)
   224	{
   225		csd->flags = 0;
   226		csd->func = func;
   227		csd->info = rq;
   228	}
   229	

---
0-DAY CI Kernel Test Service, Intel Corporation
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Attachment: .config.gz
Description: application/gzip