linux-kernel - Re: [PATCH V7 11/11] sched: Add kernel parameter to enable delaying RT threads

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Message-ID: <202507252357.llkbFyOC-lkp@intel.com>
Date: Fri, 25 Jul 2025 23:52:35 +0800
From: kernel test robot <lkp@...el.com>
To: Prakash Sangappa <prakash.sangappa@...cle.com>,
	linux-kernel@...r.kernel.org
Cc: oe-kbuild-all@...ts.linux.dev, peterz@...radead.org,
	rostedt@...dmis.org, mathieu.desnoyers@...icios.com,
	tglx@...utronix.de, bigeasy@...utronix.de, kprateek.nayak@....com,
	vineethr@...ux.ibm.com, prakash.sangappa@...cle.com
Subject: Re: [PATCH V7 11/11] sched: Add kernel parameter to enable delaying
 RT threads

Hi Prakash,

kernel test robot noticed the following build errors:

[auto build test ERROR on tip/x86/core]
[also build test ERROR on linus/master v6.16-rc7]
[cannot apply to tip/sched/core tip/core/entry next-20250725]
[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/sched-Scheduler-time-slice-extension/20250725-002052
base:   tip/x86/core
patch link:    https://lore.kernel.org/r/20250724161625.2360309-12-prakash.sangappa%40oracle.com
patch subject: [PATCH V7 11/11] sched: Add kernel parameter to enable delaying RT threads
config: riscv-randconfig-001-20250725 (https://download.01.org/0day-ci/archive/20250725/202507252357.llkbFyOC-lkp@intel.com/config)
compiler: riscv64-linux-gcc (GCC) 10.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250725/202507252357.llkbFyOC-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@...el.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202507252357.llkbFyOC-lkp@intel.com/

All errors (new ones prefixed by >>):

   kernel/entry/common.c: In function 'rseq_delay_resched':
>> kernel/entry/common.c:96:11: error: 'sysctl_sched_delay_rt' undeclared (first use in this function)
      96 |  tiflag = sysctl_sched_delay_rt ? _TIF_NEED_RESCHED|_TIF_NEED_RESCHED_LAZY :
         |           ^~~~~~~~~~~~~~~~~~~~~
   kernel/entry/common.c:96:11: note: each undeclared identifier is reported only once for each function it appears in


vim +/sysctl_sched_delay_rt +96 kernel/entry/common.c

    85	
    86	static inline bool rseq_delay_resched(unsigned long ti_work)
    87	{
    88		unsigned long tiflag;
    89	
    90		if (!IS_ENABLED(CONFIG_RSEQ_RESCHED_DELAY))
    91			return false;
    92	
    93		if (unlikely(current->rseq_delay_resched != RSEQ_RESCHED_DELAY_PROBE))
    94			return false;
    95	
  > 96		tiflag = sysctl_sched_delay_rt ? _TIF_NEED_RESCHED|_TIF_NEED_RESCHED_LAZY :
    97			 _TIF_NEED_RESCHED_LAZY;
    98	
    99		if (!(ti_work & tiflag))
   100			return false;
   101	
   102		if (__rseq_delay_resched()) {
   103			clear_tsk_need_resched(current);
   104			trace_sched_delay_resched(current, ti_work);
   105			return true;
   106		}
   107		return false;
   108	}
   109	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki