Re: [PATCH 8/8] mm/vmstat, memcontrol: Track ZSWAP_B, ZSWAPPED_B per-memcg-lruvec

[Joshua Hahn]

On Fri, 27 Feb 2026 06:40:18 +0800 kernel test robot <lkp@xxxxxxxxx> wrote:

> Hi Joshua,
> 
> kernel test robot noticed the following build errors:
> 
> [auto build test ERROR on axboe/for-next]
> [also build test ERROR on linus/master v7.0-rc1]
> [cannot apply to akpm-mm/mm-everything next-20260226]
> [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/Joshua-Hahn/mm-zsmalloc-Rename-zs_object_copy-to-zs_obj_copy/20260227-033239
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git for-next
> patch link:    https://lore.kernel.org/r/20260226192936.3190275-9-joshua.hahnjy%40gmail.com
> patch subject: [PATCH 8/8] mm/vmstat, memcontrol: Track ZSWAP_B, ZSWAPPED_B per-memcg-lruvec
> config: powerpc64-randconfig-r072-20260227 (https://download.01.org/0day-ci/archive/20260227/202602270607.dJP65LGH-lkp@xxxxxxxxx/config)
> compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
> smatch version: v0.5.0-8994-gd50c5a4c
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260227/202602270607.dJP65LGH-lkp@xxxxxxxxx/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@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202602270607.dJP65LGH-lkp@xxxxxxxxx/
> 
> All errors (new ones prefixed by >>):
> 
> >> mm/zsmalloc.c:813:17: error: call to undeclared function 'zpdesc_objcgs'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>      813 |         bool objcg = !!zpdesc_objcgs(zspage->first_zpdesc);
>          |                        ^
>    1 error generated.

Hi Kernel test robot,

Thanks again, this seems like the same problem of not defining
zpdesc_objcgs outside for the !ifdef CONFIG_MEMCG case. However, in this
case I think the change that needs to be made is actually to make the
charging happen unconditionally, and within the charging functions
check if objcg is present, since the node states can be updated even
without the concept of a memcg.

Thanks again!
Joshua