Re: [RESEND PATCH v11 1/2] sched/deadline: Add support for SD_PREFER_SIBLING on find_later_rq()

[Byungchul Park <byungchul.park@lge.com>]

On 1/11/2018 2:22 AM, kbuild test robot wrote:
> Hi Byungchul,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on tip/sched/core]
> [also build test WARNING on v4.15-rc7 next-20180110]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> 
> url:    https://github.com/0day-ci/linux/commits/Byungchul-Park/sched-deadline-Add-support-for-SD_PREFER_SIBLING-on-find_later_rq/20180110-225946
> reproduce:
>          # apt-get install sparse
>          make ARCH=x86_64 allmodconfig
>          make C=1 CF=-D__CHECK_ENDIAN__
> 
> 
> sparse warnings: (new ones prefixed by >>)
> 
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/deadline.c:1124:5: sparse: symbol 'grub_reclaim' was not declared. Should it be
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/deadline.c:1916:9: sparse: incompatible types in comparison expression (different address spaces)
>     kernel/sched/sched.h:2104:16: sparse: incompatible types in comparison expression (different address spaces)
>>> kernel/sched/deadline.c:1857:55: sparse: incorrect type in argument 1 (different modifiers) @@ expected struct sched_domain @@ got structstruct sched_domain @@
>     kernel/sched/deadline.c:1857:55: expected struct sched_domain
>     kernel/sched/deadline.c:1857:55: got struct sched_domain const
>     kernel/sched/deadline.c:1858:64: sparse: incorrect type in argument 1 (different modifiers) @@ expected struct sched_domain @@ got structstruct sched_domain @@
>     kernel/sched/deadline.c:1858:64: expected struct sched_domain
>     kernel/sched/deadline.c:1858:64: got struct sched_domain const
>     kernel/sched/deadline.c:563:9: sparse: context imbalance in 'dl_task_offline_migration' - unexpected unlock
>     kernel/sched/deadline.c:2060:9: sparse: context imbalance in 'find_lock_later_rq' - different lock contexts for basic block
>     kernel/sched/deadline.c:2155:23: sparse: context imbalance in 'push_dl_task' - unexpected unlock
>     kernel/sched/sched.h:1856:17: sparse: context imbalance in 'pull_dl_task' - unexpected unlock
>     kernel/sched/deadline.c: In function 'find_cpu':
>     kernel/sched/deadline.c:1857:48: warning: passing argument 1 of 'sched_domain_span' discards 'const' qualifier from pointer target type
>      const struct cpumask = sched_domain_span(sd);
>      ^~
>     In file included from kernel/sched/sched.h:6:0,
>      from kernel/sched/deadline.c:18:
>     include/linux/sched/topology.h:160:31: note: expected 'struct sched_domain but argument is of type 'const struct sched_domain
>      static inline struct cpumask sched_domain
>      ^~~~~~~~~~~~~~~~~
>     kernel/sched/deadline.c:1858:57: warning: passing argument 1 of 'sched_domain_span' discards 'const' qualifier from pointer target type
>      const struct cpumask = prefer sched_domain_span(prefer) : NULL;
>      ^~~~~~
>     In file included from kernel/sched/sched.h:6:0,
>      from kernel/sched/deadline.c:18:
>     include/linux/sched/topology.h:160:31: note: expected 'struct sched_domain but argument is of type 'const struct sched_domain
>      static inline struct cpumask sched_domain
>      ^~~~~~~~~~~~~~~~~
> 
> vim +1857 kernel/sched/deadline.c
> 
>    1849	
>    1850	/*
>    1851	 * Find the first cpu in: mask & sd & ~prefer
>    1852	 */
>    1853	static int find_cpu(const struct cpumask *mask,
>    1854			    const struct sched_domain *sd,
>    1855			    const struct sched_domain *prefer)
>    1856	{
>> 1857		const struct cpumask *sds = sched_domain_span(sd);

Thanks a lot.

I will fix and respin it.

I'm gonna change prototype of sched_domain_span() rather than
find_cpu() to avoid the warning. Is it ok to fix it that way?

>    1858		const struct cpumask *ps  = prefer ? sched_domain_span(prefer) : NULL;
>    1859		int cpu;
>    1860	
>    1861		for_each_cpu(cpu, mask) {
>    1862			if (!cpumask_test_cpu(cpu, sds))
>    1863				continue;
>    1864			if (ps && cpumask_test_cpu(cpu, ps))
>    1865				continue;
>    1866			break;
>    1867		}
>    1868	
>    1869		return cpu;
>    1870	}
>    1871	
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
> 

-- 
Thanks,
Byungchul