Re: [PATCH v2] stackdepot: Make max number of pools build-time configurable

[Marco Elver <elver@google.com>]

On Sat, 5 Jul 2025 at 08:01, kernel test robot <lkp@intel.com> wrote:
>
> Hi Matt,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on akpm-mm/mm-nonmm-unstable]
> [also build test ERROR on linus/master v6.16-rc4 next-20250704]
> [cannot apply to akpm-mm/mm-everything]
> [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/Matt-Fleming/stackdepot-Make-max-number-of-pools-build-time-configurable/20250704-200804
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-nonmm-unstable
> patch link:    https://lore.kernel.org/r/20250704120604.2688934-1-matt%40readmodwrite.com
> patch subject: [PATCH v2] stackdepot: Make max number of pools build-time configurable
> config: arm64-randconfig-001-20250705 (https://download.01.org/0day-ci/archive/20250705/202507051300.E0JSHxu1-lkp@intel.com/config)
> compiler: aarch64-linux-gcc (GCC) 10.5.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250705/202507051300.E0JSHxu1-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/202507051300.E0JSHxu1-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
>    In file included from include/linux/init.h:5,
>                     from include/linux/printk.h:6,
>                     from include/asm-generic/bug.h:22,
>                     from arch/arm64/include/asm/bug.h:26,
>                     from include/linux/bug.h:5,
>                     from include/linux/vfsdebug.h:5,
>                     from include/linux/fs.h:5,
>                     from include/linux/debugfs.h:15,
>                     from lib/stackdepot.c:17:
> >> include/linux/build_bug.h:78:41: error: static assertion failed: "DEPOT_MAX_POOLS <= (1LL << (DEPOT_POOL_INDEX_BITS)) - 1"
>       78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
>          |                                         ^~~~~~~~~~~~~~
>    include/linux/build_bug.h:77:34: note: in expansion of macro '__static_assert'
>       77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
>          |                                  ^~~~~~~~~~~~~~~
>    lib/stackdepot.c:42:1: note: in expansion of macro 'static_assert'
>       42 | static_assert(DEPOT_MAX_POOLS <= (1LL << (DEPOT_POOL_INDEX_BITS)) - 1);
>          | ^~~~~~~~~~~~~

This is odd. The randconfig here uses the default:

> CONFIG_STACKDEPOT_MAX_POOLS=8192