Re: [PATCH -next 3/5] mm/mglru: extend shrink_one for both lrugen and non-lrugen

Chen Ridong
2025-12-12T09:54:01Z

On 2025/12/12 10:55, kernel test robot wrote:
> Hi Chen,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on akpm-mm/mm-everything]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Chen-Ridong/mm-mglru-use-mem_cgroup_iter-for-global-reclaim/20251209-094913
> base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link: https://lore.kernel.org/r/20251209012557.1949239-4-chenridong%40huaweicloud.com
> patch subject: [PATCH -next 3/5] mm/mglru: extend shrink_one for both lrugen and non-lrugen
> config: x86_64-randconfig-004-20251212 (https://download.01.org/0day-ci/archive/20251212/202512121027.03z9qd08-lkp@intel.com/config)
> compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251212/202512121027.03z9qd08-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/202512121027.03z9qd08-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
>>> mm/vmscan.o: warning: objtool: shrink_one+0xeb2: sibling call from callable instruction with modified stack frame
>

This is the first time I've encountered this warning. While adding
`STACK_FRAME_NON_STANDARD(shrink_one)` resolves it, I noticed this approach isn't widely used in the
codebase. Is this the standard solution, or are there better alternatives?

I've tested that the warning persists even when `shrink_one` is simplified to only call `shrink_lruvec`:

```
static void shrink_one(struct lruvec *lruvec, struct scan_control *sc)
{
shrink_lruvec(lruvec, sc);
}
```

How can we properly avoid this warning without using STACK_FRAME_NON_STANDARD?

--
Best regards,
Ridong