Re: [PATCH] mm: huge_memory: a new debugfs interface for splitting THP tests.

[kernel test robot]

Hi Zi,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kselftest/next]
[also build test ERROR on linux/master linus/master v5.12-rc2 next-20210305]
[cannot apply to hnaz-linux-mm/master]
[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/Zi-Yan/mm-huge_memory-a-new-debugfs-interface-for-splitting-THP-tests/20210308-232339
base:   https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
config: x86_64-randconfig-a015-20210308 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 3a11a41795bec548e91621caaa4cc00fc31b2212)
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 x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/961321af55684845ebc1e13e4c4e7c0da14a476a
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Zi-Yan/mm-huge_memory-a-new-debugfs-interface-for-splitting-THP-tests/20210308-232339
        git checkout 961321af55684845ebc1e13e4c4e7c0da14a476a
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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

All errors (new ones prefixed by >>):

>> mm/huge_memory.c:3026:40: error: implicit declaration of function 'vma_migratable' [-Werror,-Wimplicit-function-declaration]
                   if (!vma || addr < vma->vm_start || !vma_migratable(vma))
                                                        ^
   1 error generated.


vim +/vma_migratable +3026 mm/huge_memory.c

  2930	
  2931	#ifdef CONFIG_DEBUG_FS
  2932	static int split_huge_pages_set(void *data, u64 val)
  2933	{
  2934		struct zone *zone;
  2935		struct page *page;
  2936		unsigned long pfn, max_zone_pfn;
  2937		unsigned long total = 0, split = 0;
  2938	
  2939		if (val != 1)
  2940			return -EINVAL;
  2941	
  2942		for_each_populated_zone(zone) {
  2943			max_zone_pfn = zone_end_pfn(zone);
  2944			for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) {
  2945				if (!pfn_valid(pfn))
  2946					continue;
  2947	
  2948				page = pfn_to_page(pfn);
  2949				if (!get_page_unless_zero(page))
  2950					continue;
  2951	
  2952				if (zone != page_zone(page))
  2953					goto next;
  2954	
  2955				if (!PageHead(page) || PageHuge(page) || !PageLRU(page))
  2956					goto next;
  2957	
  2958				total++;
  2959				lock_page(page);
  2960				if (!split_huge_page(page))
  2961					split++;
  2962				unlock_page(page);
  2963	next:
  2964				put_page(page);
  2965			}
  2966		}
  2967	
  2968		pr_info("%lu of %lu THP split\n", split, total);
  2969	
  2970		return 0;
  2971	}
  2972	DEFINE_DEBUGFS_ATTRIBUTE(split_huge_pages_fops, NULL, split_huge_pages_set,
  2973			"%llu\n");
  2974	
  2975	static ssize_t split_huge_pages_in_range_pid_write(struct file *file,
  2976			const char __user *buf, size_t count, loff_t *ppops)
  2977	{
  2978		static DEFINE_MUTEX(mutex);
  2979		ssize_t ret;
  2980		char input_buf[80]; /* hold pid, start_vaddr, end_vaddr */
  2981		int pid;
  2982		unsigned long vaddr_start, vaddr_end, addr;
  2983		nodemask_t task_nodes;
  2984		struct mm_struct *mm;
  2985		unsigned long total = 0, split = 0;
  2986	
  2987		ret = mutex_lock_interruptible(&mutex);
  2988		if (ret)
  2989			return ret;
  2990	
  2991		ret = -EFAULT;
  2992	
  2993		memset(input_buf, 0, 80);
  2994		if (copy_from_user(input_buf, buf, min_t(size_t, count, 80)))
  2995			goto out;
  2996	
  2997		input_buf[79] = '\0';
  2998		ret = sscanf(input_buf, "%d,0x%lx,0x%lx", &pid, &vaddr_start, &vaddr_end);
  2999		if (ret != 3) {
  3000			ret = -EINVAL;
  3001			goto out;
  3002		}
  3003		vaddr_start &= PAGE_MASK;
  3004		vaddr_end &= PAGE_MASK;
  3005	
  3006		ret = strlen(input_buf);
  3007		pr_debug("split huge pages in pid: %d, vaddr: [%lx - %lx]\n",
  3008			 pid, vaddr_start, vaddr_end);
  3009	
  3010		mm = find_mm_struct(pid, &task_nodes);
  3011		if (IS_ERR(mm)) {
  3012			ret = -EINVAL;
  3013			goto out;
  3014		}
  3015	
  3016		mmap_read_lock(mm);
  3017		/*
  3018		 * always increase addr by PAGE_SIZE, since we could have a PTE page
  3019		 * table filled with PTE-mapped THPs, each of which is distinct.
  3020		 */
  3021		for (addr = vaddr_start; addr < vaddr_end; addr += PAGE_SIZE) {
  3022			struct vm_area_struct *vma = find_vma(mm, addr);
  3023			unsigned int follflags;
  3024			struct page *page;
  3025	
> 3026			if (!vma || addr < vma->vm_start || !vma_migratable(vma))
  3027				break;
  3028	
  3029			/* FOLL_DUMP to ignore special (like zero) pages */
  3030			follflags = FOLL_GET | FOLL_DUMP;
  3031			page = follow_page(vma, addr, follflags);
  3032	
  3033			if (IS_ERR(page))
  3034				break;
  3035			if (!page)
  3036				break;
  3037	
  3038			if (!is_transparent_hugepage(page))
  3039				continue;
  3040	
  3041			total++;
  3042			if (!can_split_huge_page(compound_head(page), NULL))
  3043				continue;
  3044	
  3045			if (!trylock_page(page))
  3046				continue;
  3047	
  3048			if (!split_huge_page(page))
  3049				split++;
  3050	
  3051			unlock_page(page);
  3052			put_page(page);
  3053		}
  3054		mmap_read_unlock(mm);
  3055		mmput(mm);
  3056	
  3057		pr_debug("%lu of %lu THP split\n", split, total);
  3058	out:
  3059		mutex_unlock(&mutex);
  3060		return ret;
  3061	

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

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