Re: [patch V4 1/2] smp: Rename flush_smp_call_function_from_idle()

From: kernel test robot
Date: Tue Apr 12 2022 - 22:53:36 EST


Hi Thomas,

I love your patch! Perhaps something to improve:

[auto build test WARNING on tip/sched/core]
[also build test WARNING on hch-configfs/for-next linus/master linux/master v5.18-rc2 next-20220412]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/intel-lab-lkp/linux/commits/Thomas-Gleixner/smp-Make-softirq-handling-RT-friendly/20220413-045944
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 089c02ae2771a14af2928c59c56abfb9b885a8d7
config: hexagon-defconfig (https://download.01.org/0day-ci/archive/20220413/202204131056.b582vtMv-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project fe2478d44e4f7f191c43fef629ac7a23d0251e72)
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
# https://github.com/intel-lab-lkp/linux/commit/7c7c3b99f3599eb409f237b32f330fa06bffcd5d
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Thomas-Gleixner/smp-Make-softirq-handling-RT-friendly/20220413-045944
git checkout 7c7c3b99f3599eb409f237b32f330fa06bffcd5d
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash

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

All warnings (new ones prefixed by >>):

>> kernel/smp.c:697:6: warning: no previous prototype for function 'flush_smp_call_function_queue' [-Wmissing-prototypes]
void flush_smp_call_function_queue(void)
^
kernel/smp.c:697:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void flush_smp_call_function_queue(void)
^
static
1 warning generated.


vim +/flush_smp_call_function_queue +697 kernel/smp.c

683
684
685 /**
686 * flush_smp_call_function_queue - Flush pending smp-call-function callbacks
687 * from task context (idle, migration thread)
688 *
689 * When TIF_POLLING_NRFLAG is supported and a CPU is in idle and has it
690 * set, then remote CPUs can avoid sending IPIs and wake the idle CPU by
691 * setting TIF_NEED_RESCHED. The idle task on the woken up CPU has to
692 * handle queued SMP function calls before scheduling.
693 *
694 * The migration thread has to ensure that an eventually pending wakeup has
695 * been handled before it migrates a task.
696 */
> 697 void flush_smp_call_function_queue(void)
698 {
699 unsigned long flags;
700
701 if (llist_empty(this_cpu_ptr(&call_single_queue)))
702 return;
703
704 cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->idle, CFD_SEQ_NOCPU,
705 smp_processor_id(), CFD_SEQ_IDLE);
706 local_irq_save(flags);
707 __flush_smp_call_function_queue(true);
708 if (local_softirq_pending())
709 do_softirq();
710
711 local_irq_restore(flags);
712 }
713

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