* Re: [PATCH 3/4] mm: prevent KSM from completely breaking VMA merging
2025-05-19 13:19 ` [PATCH 3/4] mm: prevent KSM from completely breaking VMA merging kernel test robot
@ 2025-05-19 13:36 ` Lorenzo Stoakes
0 siblings, 0 replies; 2+ messages in thread
From: Lorenzo Stoakes @ 2025-05-19 13:36 UTC (permalink / raw)
To: Andrew Morton
Cc: kernel test robot, llvm, oe-kbuild-all,
Linux Memory Management List, Alexander Viro, Christian Brauner,
Jan Kara, Liam R . Howlett, Vlastimil Babka, Jann Horn,
Pedro Falcato, David Hildenbrand, Xu Xin, Chengming Zhou,
linux-kernel, linux-fsdevel
Andrew - fix-patch enclosed for this. Silly oversight.
Will also fixup on any respin.
Thanks, Lorenzo
On Mon, May 19, 2025 at 09:19:50PM +0800, kernel test robot wrote:
> Hi Lorenzo,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on akpm-mm/mm-everything]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Lorenzo-Stoakes/mm-ksm-have-KSM-VMA-checks-not-require-a-VMA-pointer/20250519-165315
> base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link: https://lore.kernel.org/r/418d3edbec3a718a7023f1beed5478f5952fc3df.1747431920.git.lorenzo.stoakes%40oracle.com
> patch subject: [PATCH 3/4] mm: prevent KSM from completely breaking VMA merging
> config: x86_64-buildonly-randconfig-001-20250519 (https://download.01.org/0day-ci/archive/20250519/202505192132.NsAm4haK-lkp@intel.com/config)
> compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250519/202505192132.NsAm4haK-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/202505192132.NsAm4haK-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> >> mm/vma.c:2589:15: error: call to undeclared function 'ksm_vma_flags'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> 2589 | map->flags = ksm_vma_flags(map->mm, map->file, map->flags);
> | ^
> mm/vma.c:2761:10: error: call to undeclared function 'ksm_vma_flags'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> 2761 | flags = ksm_vma_flags(mm, NULL, flags);
> | ^
> 2 errors generated.
Ugh ok looks like I forgot to provide an #else for the #ifdef CONFIG_KSM here.
>
>
> vim +/ksm_vma_flags +2589 mm/vma.c
>
> 2586
> 2587 static void update_ksm_flags(struct mmap_state *map)
> 2588 {
> > 2589 map->flags = ksm_vma_flags(map->mm, map->file, map->flags);
> 2590 }
> 2591
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
----8<----
From 2dbb9c4471f6145a513b5a2a661c78d3269fc9fe Mon Sep 17 00:00:00 2001
From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Date: Mon, 19 May 2025 14:36:14 +0100
Subject: [PATCH] fix
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
include/linux/ksm.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index ba5664daca6e..febc8acc565d 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -97,8 +97,11 @@ bool ksm_process_mergeable(struct mm_struct *mm);
#else /* !CONFIG_KSM */
-static inline void ksm_add_vma(struct vm_area_struct *vma)
+static inline vm_flags_t ksm_vma_flags(const struct mm_struct *mm,
+ const struct file *file,
+ vm_flags_t vm_flags)
{
+ return vm_flags;
}
static inline int ksm_disable(struct mm_struct *mm)
--
2.49.0
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