Re: [PATCH v2 09/12] mm/vm_debug_pgtable: Use struct pgtable_debug_args in PUD modifying tests

[Gavin Shan]

On 7/19/21 7:13 PM, kernel test robot wrote:
> Hi Gavin,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on linus/master]
> [also build test WARNING on v5.14-rc2]
> [cannot apply to hnaz-linux-mm/master linux/master next-20210716]
> [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]
>
> url:    https://github.com/0day-ci/linux/commits/Gavin-Shan/mm-debug_vm_pgtable-Enhancements/20210719-134236
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2734d6c1b1a089fb593ef6a23d4b70903526fe0c
> config: arm64-randconfig-r005-20210719 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 5d5b08761f944d5b9822d582378333cc4b36a0a7)
> reproduce (this is a W=1 build):
>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>          chmod +x ~/bin/make.cross
>          # install arm64 cross compiling tool for clang build
>          # apt-get install binutils-aarch64-linux-gnu
>          # https://github.com/0day-ci/linux/commit/69db26024e6bd48423ebc83b0f83b7b52217b624
>          git remote add linux-review https://github.com/0day-ci/linux
>          git fetch --no-tags linux-review Gavin-Shan/mm-debug_vm_pgtable-Enhancements/20210719-134236
>          git checkout 69db26024e6bd48423ebc83b0f83b7b52217b624
>          # save the attached .config to linux build tree
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>

Thanks for reporting the build warnings. I will fix it in v3.

> All warnings (new ones prefixed by >>):
>
> > > mm/debug_vm_pgtable.c:445:8: warning: variable 'pud' set but not used [-Wunused-but-set-variable]
>             pud_t pud;
>  

A "WARN_ON(!pud_none(pud)) is missed from PATCH[9/12].

                 ^
>     mm/debug_vm_pgtable.c:1140:17: warning: variable 'protnone' set but not used [-Wunused-but-set-variable]
>             pgprot_t prot, protnone;
>                            ^
>     mm/debug_vm_pgtable.c:1142:36: warning: variable 'pmd_aligned' set but not used [-Wunused-but-set-variable]
>             unsigned long vaddr, pte_aligned, pmd_aligned;
>                                               ^
>     mm/debug_vm_pgtable.c:1143:42: warning: variable 'pgd_aligned' set but not used [-Wunused-but-set-variable]
>             unsigned long pud_aligned, p4d_aligned, pgd_aligned;
>                                                     ^
>     mm/debug_vm_pgtable.c:1143:29: warning: variable 'p4d_aligned' set but not used [-Wunused-but-set-variable]
>             unsigned long pud_aligned, p4d_aligned, pgd_aligned;
>                                        ^
>     mm/debug_vm_pgtable.c:1143:16: warning: variable 'pud_aligned' set but not used [-Wunused-but-set-variable]
>             unsigned long pud_aligned, p4d_aligned, pgd_aligned;
>                           ^
>     mm/debug_vm_pgtable.c:1140:11: warning: variable 'prot' set but not used [-Wunused-but-set-variable]
>             pgprot_t prot, protnone;
>                      ^
>     7 warnings generated.

There are more build warnings introduced by other patches. I need to drop the unused
variables in debug_vm_pgtable(). So I need to drop the unused variables in separate
patches in v3, instead of dropping all of them in PATCH[v2 11/12].

Thanks,
Gavin

> vim +/pud +445 mm/debug_vm_pgtable.c
>
> 5fe77be6bf14bf Shixin Liu        2021-06-30  442
> 69db26024e6bd4 Gavin Shan        2021-07-19  443  static void __init pud_huge_tests(struct pgtable_debug_args *args)
> a5c3b9ffb0f404 Anshuman Khandual 2020-08-06  444  {
> 5fe77be6bf14bf Shixin Liu        2021-06-30 @445  	pud_t pud;
> 5fe77be6bf14bf Shixin Liu        2021-06-30  446
> 69db26024e6bd4 Gavin Shan        2021-07-19  447  	if (!arch_vmap_pud_supported(args->page_prot))
> 5fe77be6bf14bf Shixin Liu        2021-06-30  448  		return;
> 5fe77be6bf14bf Shixin Liu        2021-06-30  449
> 5fe77be6bf14bf Shixin Liu        2021-06-30  450  	pr_debug("Validating PUD huge\n");
> 5fe77be6bf14bf Shixin Liu        2021-06-30  451  	/*
> 5fe77be6bf14bf Shixin Liu        2021-06-30  452  	 * X86 defined pud_set_huge() verifies that the given
> 5fe77be6bf14bf Shixin Liu        2021-06-30  453  	 * PUD is not a populated non-leaf entry.
> 5fe77be6bf14bf Shixin Liu        2021-06-30  454  	 */
> 69db26024e6bd4 Gavin Shan        2021-07-19  455  	WRITE_ONCE(*(args->pudp), __pud(0));
> 69db26024e6bd4 Gavin Shan        2021-07-19  456  	WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn),
> 69db26024e6bd4 Gavin Shan        2021-07-19  457  			      args->page_prot));
> 69db26024e6bd4 Gavin Shan        2021-07-19  458  	WARN_ON(!pud_clear_huge(args->pudp));
> 69db26024e6bd4 Gavin Shan        2021-07-19  459  	pud = READ_ONCE(*(args->pudp));
> a5c3b9ffb0f404 Anshuman Khandual 2020-08-06  460  }
> 5fe77be6bf14bf Shixin Liu        2021-06-30  461  #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
> 54b1f4b50ddb0f Gavin Shan        2021-07-19  462  static void __init pmd_huge_tests(struct pgtable_debug_args *args) { }
> 69db26024e6bd4 Gavin Shan        2021-07-19  463  static void __init pud_huge_tests(struct pgtable_debug_args *args) { }
> 5fe77be6bf14bf Shixin Liu        2021-06-30  464  #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
> 399145f9eb6c67 Anshuman Khandual 2020-06-04  465
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
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