Re: [PATCH v3 3/5] sched/fair: Switch to task based throttle model

[Aaron Lu <ziqianlu@bytedance.com>]

Hi Oliver,

On Wed, Jul 23, 2025 at 04:21:59PM +0800, Oliver Sang wrote:
> hi, Aaron,
> 
> On Thu, Jul 17, 2025 at 11:52:43AM +0800, Aaron Lu wrote:
> > On Wed, Jul 16, 2025 at 11:20:55PM +0800, kernel test robot wrote:
> > > Hi Aaron,
> > > 
> > > kernel test robot noticed the following build warnings:
> > > 
> > > [auto build test WARNING on tip/sched/core]
> > > [also build test WARNING on next-20250716]
> > > [cannot apply to linus/master v6.16-rc6]
> > > [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/Aaron-Lu/sched-fair-Add-related-data-structure-for-task-based-throttle/20250715-152307
> > > base:   tip/sched/core
> > > patch link:    https://lore.kernel.org/r/20250715071658.267-4-ziqianlu%40bytedance.com
> > > patch subject: [PATCH v3 3/5] sched/fair: Switch to task based throttle model
> > > config: xtensa-randconfig-r121-20250716 (https://download.01.org/0day-ci/archive/20250716/202507162238.qiw7kyu0-lkp@intel.com/config)
> > > compiler: xtensa-linux-gcc (GCC) 8.5.0
> > > reproduce: (https://download.01.org/0day-ci/archive/20250716/202507162238.qiw7kyu0-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/202507162238.qiw7kyu0-lkp@intel.com/
> > > 
> > > sparse warnings: (new ones prefixed by >>)
> > >    kernel/sched/core.c: note: in included file (through arch/xtensa/include/asm/bitops.h, include/linux/bitops.h, include/linux/thread_info.h, ...):
> > >    arch/xtensa/include/asm/processor.h:105:2: sparse: sparse: Unsupported xtensa ABI
> > >    arch/xtensa/include/asm/processor.h:135:2: sparse: sparse: Unsupported Xtensa ABI
> > >    kernel/sched/core.c: note: in included file:
> > > >> kernel/sched/sched.h:741:44: sparse: sparse: dubious one-bit signed bitfield
> > 
> > Same problem as last report.
> > 
> > I've downloaded this compiler from kernel.org and confirmed there is no
> > such warnings after using bool.
> 
> 
> want to confirm, do you mean you can reproduce the build sparse error
> > kernel/sched/sched.h:741:44: sparse: sparse: dubious one-bit signed bitfield
>

Right.

> 
> then after doing below change:
> 
> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index 3c3ea0089b0b5..6eb15b00edccd 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -738,7 +738,7 @@ struct cfs_rq {
>         u64                     throttled_clock_pelt_time;
>         u64                     throttled_clock_self;
>         u64                     throttled_clock_self_time;
> -       int                     throttled:1;
> +       bool                    throttled:1;
>         int                     pelt_clock_throttled:1;
>         int                     throttle_count;
>         struct list_head        throttled_list;
> 
> 
> the issue will disappear?
> 

Yes, that's correct.