Re: [PATCH v1 05/12] mm: thp: introduce folio_split_queue_lock{_irqsave}()

From: kernel test robot
Date: Sat Aug 14 2021 - 04:23:10 EST

Hi Muchun,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on next-20210813]
[cannot apply to hnaz-linux-mm/master cgroup/for-next linus/master v5.14-rc5 v5.14-rc4 v5.14-rc3 v5.14-rc5]
[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/Muchun-Song/Use-obj_cgroup-APIs-to-charge-the-LRU-pages/20210814-132844
base: 4b358aabb93a2c654cd1dcab1a25a589f6e2b153
config: s390-randconfig-r044-20210814 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 1f7b25ea76a925aca690da28de9d78db7ca99d0c)
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 s390 cross compiling tool for clang build
# apt-get install binutils-s390x-linux-gnu
# https://github.com/0day-ci/linux/commit/3460bcf13b968edf6f4621c0e0dcde46500957e5
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Muchun-Song/Use-obj_cgroup-APIs-to-charge-the-LRU-pages/20210814-132844
git checkout 3460bcf13b968edf6f4621c0e0dcde46500957e5
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

In file included from mm/huge_memory.c:16:
In file included from include/linux/rmap.h:12:
In file included from include/linux/memcontrol.h:22:
In file included from include/linux/writeback.h:14:
In file included from include/linux/blk-cgroup.h:23:
In file included from include/linux/blkdev.h:23:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:36:59: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
^
include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
#define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
^
In file included from mm/huge_memory.c:16:
In file included from include/linux/rmap.h:12:
In file included from include/linux/memcontrol.h:22:
In file included from include/linux/writeback.h:14:
In file included from include/linux/blk-cgroup.h:23:
In file included from include/linux/blkdev.h:23:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
#define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
^
In file included from mm/huge_memory.c:16:
In file included from include/linux/rmap.h:12:
In file included from include/linux/memcontrol.h:22:
In file included from include/linux/writeback.h:14:
In file included from include/linux/blk-cgroup.h:23:
In file included from include/linux/blkdev.h:23:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> mm/huge_memory.c:2797:21: warning: variable 'memcg' set but not used [-Wunused-but-set-variable]
struct mem_cgroup *memcg;
^
13 warnings generated.


vim +/memcg +2797 mm/huge_memory.c

2793
2794 void deferred_split_huge_page(struct page *page)
2795 {
2796 struct deferred_split *ds_queue;
> 2797 struct mem_cgroup *memcg;
2798 unsigned long flags;
2799
2800 VM_BUG_ON_PAGE(!PageTransHuge(page), page);
2801
2802 /*
2803 * The try_to_unmap() in page reclaim path might reach here too,
2804 * this may cause a race condition to corrupt deferred split queue.
2805 * And, if page reclaim is already handling the same page, it is
2806 * unnecessary to handle it again in shrinker.
2807 *
2808 * Check PageSwapCache to determine if the page is being
2809 * handled by page reclaim since THP swap would add the page into
2810 * swap cache before calling try_to_unmap().
2811 */
2812 if (PageSwapCache(page))
2813 return;
2814
2815 ds_queue = folio_split_queue_lock_irqsave(page_folio(page), &flags);
2816 memcg = split_queue_memcg(ds_queue);
2817 if (list_empty(page_deferred_list(page))) {
2818 count_vm_event(THP_DEFERRED_SPLIT_PAGE);
2819 list_add_tail(page_deferred_list(page), &ds_queue->split_queue);
2820 ds_queue->split_queue_len++;
2821 #ifdef CONFIG_MEMCG
2822 if (memcg)
2823 set_shrinker_bit(memcg, page_to_nid(page),
2824 deferred_split_shrinker.id);
2825 #endif
2826 }
2827 split_queue_unlock_irqrestore(ds_queue, flags);
2828 }
2829

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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