Re: [RFC PATCH 2/4] Scheduler time extention

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

Hi Prakash,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on linus/master v6.12-rc7]
[cannot apply to tip/sched/core tip/x86/asm tip/core/entry next-20241113]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Prakash-Sangappa/Introduce-per-thread-user-kernel-shared-structure/20241113-082854
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20241113000126.967713-3-prakash.sangappa%40oracle.com
patch subject: [RFC PATCH 2/4] Scheduler time extention
config: x86_64-rhel-8.3 (https://download.01.org/0day-ci/archive/20241114/202411140916.EaVa0bnv-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241114/202411140916.EaVa0bnv-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411140916.EaVa0bnv-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/entry/common.c:93: warning: Function parameter or struct member 'irq' not described in 'exit_to_user_mode_loop'


vim +93 kernel/entry/common.c

a9f3a74a29af09 Thomas Gleixner     2020-07-22   84  
d68019471995ba Sven Schnelle       2023-12-18   85  /**
d68019471995ba Sven Schnelle       2023-12-18   86   * exit_to_user_mode_loop - do any pending work before leaving to user space
d68019471995ba Sven Schnelle       2023-12-18   87   * @regs:	Pointer to pt_regs on entry stack
d68019471995ba Sven Schnelle       2023-12-18   88   * @ti_work:	TIF work flags as read by the caller
d68019471995ba Sven Schnelle       2023-12-18   89   */
d68019471995ba Sven Schnelle       2023-12-18   90  __always_inline unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
4d4270d40543ca Prakash Sangappa    2024-11-13   91  						     unsigned long ti_work,
4d4270d40543ca Prakash Sangappa    2024-11-13   92  						     bool irq)
a9f3a74a29af09 Thomas Gleixner     2020-07-22  @93  {
a9f3a74a29af09 Thomas Gleixner     2020-07-22   94  	/*
a9f3a74a29af09 Thomas Gleixner     2020-07-22   95  	 * Before returning to user space ensure that all pending work
a9f3a74a29af09 Thomas Gleixner     2020-07-22   96  	 * items have been completed.
a9f3a74a29af09 Thomas Gleixner     2020-07-22   97  	 */
a9f3a74a29af09 Thomas Gleixner     2020-07-22   98  	while (ti_work & EXIT_TO_USER_MODE_WORK) {
a9f3a74a29af09 Thomas Gleixner     2020-07-22   99  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  100  		local_irq_enable_exit_to_user(ti_work);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  101  
4d4270d40543ca Prakash Sangappa    2024-11-13  102  		if (ti_work & _TIF_NEED_RESCHED) {
4d4270d40543ca Prakash Sangappa    2024-11-13  103  			if (irq && taskshrd_delay_resched())
4d4270d40543ca Prakash Sangappa    2024-11-13  104  				clear_tsk_need_resched(current);
4d4270d40543ca Prakash Sangappa    2024-11-13  105  			else
a9f3a74a29af09 Thomas Gleixner     2020-07-22  106  				schedule();
4d4270d40543ca Prakash Sangappa    2024-11-13  107  		}
a9f3a74a29af09 Thomas Gleixner     2020-07-22  108  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  109  		if (ti_work & _TIF_UPROBE)
a9f3a74a29af09 Thomas Gleixner     2020-07-22  110  			uprobe_notify_resume(regs);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  111  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  112  		if (ti_work & _TIF_PATCH_PENDING)
a9f3a74a29af09 Thomas Gleixner     2020-07-22  113  			klp_update_patch_state(current);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  114  
12db8b690010cc Jens Axboe          2020-10-26  115  		if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
8ba62d37949e24 Eric W. Biederman   2022-02-09  116  			arch_do_signal_or_restart(regs);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  117  
a68de80f61f6af Sean Christopherson 2021-09-01  118  		if (ti_work & _TIF_NOTIFY_RESUME)
03248addadf1a5 Eric W. Biederman   2022-02-09  119  			resume_user_mode_work(regs);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  120  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  121  		/* Architecture specific TIF work */
a9f3a74a29af09 Thomas Gleixner     2020-07-22  122  		arch_exit_to_user_mode_work(regs, ti_work);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  123  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  124  		/*
a9f3a74a29af09 Thomas Gleixner     2020-07-22  125  		 * Disable interrupts and reevaluate the work flags as they
a9f3a74a29af09 Thomas Gleixner     2020-07-22  126  		 * might have changed while interrupts and preemption was
a9f3a74a29af09 Thomas Gleixner     2020-07-22  127  		 * enabled above.
a9f3a74a29af09 Thomas Gleixner     2020-07-22  128  		 */
a9f3a74a29af09 Thomas Gleixner     2020-07-22  129  		local_irq_disable_exit_to_user();
47b8ff194c1fd7 Frederic Weisbecker 2021-02-01  130  
47b8ff194c1fd7 Frederic Weisbecker 2021-02-01  131  		/* Check if any of the above work has queued a deferred wakeup */
f268c3737ecaef Frederic Weisbecker 2021-05-27  132  		tick_nohz_user_enter_prepare();
47b8ff194c1fd7 Frederic Weisbecker 2021-02-01  133  
6ce895128b3bff Mark Rutland        2021-11-29  134  		ti_work = read_thread_flags();
a9f3a74a29af09 Thomas Gleixner     2020-07-22  135  	}
a9f3a74a29af09 Thomas Gleixner     2020-07-22  136  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  137  	/* Return the latest work state for arch_exit_to_user_mode() */
a9f3a74a29af09 Thomas Gleixner     2020-07-22  138  	return ti_work;
a9f3a74a29af09 Thomas Gleixner     2020-07-22  139  }
a9f3a74a29af09 Thomas Gleixner     2020-07-22  140  

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