tree:   https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.10.y
head:   5e0262e1f1ac5576193112de3ecc70fd3726fee3
commit: 3c51d82d0b7862d7d246016c74b4390fb1fa1f11 [125/1180] sched/core: Initialize the idle task with preemption disabled
config: i386-randconfig-a001-20210724 (attached as .config)
compiler: gcc-10 (Ubuntu 10.3.0-1ubuntu1~20.04) 10.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=3c51d82d0b7862d7d246016c74b4390fb1fa1f11
        git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
        git fetch --no-tags linux-stable-rc linux-5.10.y
        git checkout 3c51d82d0b7862d7d246016c74b4390fb1fa1f11
        # save the attached .config to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

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

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

>> WARNING: modpost: vmlinux.o(.text.unlikely+0x12806): Section mismatch in reference from the function idle_init() to the function .init.text:fork_idle()
The function idle_init() references
the function __init fork_idle().
This is often because idle_init lacks a __init
annotation or the annotation of fork_idle is wrong.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org