Re: [PATCH v1 1/2] mm/madvise: introduce MADV_TRY_COLLAPSE for attempted synchronous hugepage collapse
From: kernel test robot
Date: Wed Jan 17 2024 - 19:32:34 EST
Hi Lance,
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/Lance-Yang/mm-madvise-add-MADV_TRY_COLLAPSE-to-process_madvise/20240117-130450
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20240117050217.43610-1-ioworker0%40gmail.com
patch subject: [PATCH v1 1/2] mm/madvise: introduce MADV_TRY_COLLAPSE for attempted synchronous hugepage collapse
config: x86_64-rhel-8.3-bpf (https://download.01.org/0day-ci/archive/20240118/202401180810.sR4s25PR-lkp@xxxxxxxxx/config)
compiler: ClangBuiltLinux clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240118/202401180810.sR4s25PR-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/202401180810.sR4s25PR-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
>> mm/khugepaged.c:2789:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
2789 | case SCAN_PMD_NULL:
| ^
mm/khugepaged.c:2789:3: note: insert '__attribute__((fallthrough));' to silence this warning
2789 | case SCAN_PMD_NULL:
| ^
| __attribute__((fallthrough));
mm/khugepaged.c:2789:3: note: insert 'break;' to avoid fall-through
2789 | case SCAN_PMD_NULL:
| ^
| break;
1 warning generated.
vim +2789 mm/khugepaged.c
7d8faaf155454f Zach O'Keefe 2022-07-06 2702
7d8faaf155454f Zach O'Keefe 2022-07-06 2703 int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
a37dacf95f1857 Lance Yang 2024-01-17 2704 unsigned long start, unsigned long end, bool is_try)
7d8faaf155454f Zach O'Keefe 2022-07-06 2705 {
7d8faaf155454f Zach O'Keefe 2022-07-06 2706 struct collapse_control *cc;
7d8faaf155454f Zach O'Keefe 2022-07-06 2707 struct mm_struct *mm = vma->vm_mm;
7d8faaf155454f Zach O'Keefe 2022-07-06 2708 unsigned long hstart, hend, addr;
7d8faaf155454f Zach O'Keefe 2022-07-06 2709 int thps = 0, last_fail = SCAN_FAIL;
7d8faaf155454f Zach O'Keefe 2022-07-06 2710 bool mmap_locked = true;
7d8faaf155454f Zach O'Keefe 2022-07-06 2711
7d8faaf155454f Zach O'Keefe 2022-07-06 2712 BUG_ON(vma->vm_start > start);
7d8faaf155454f Zach O'Keefe 2022-07-06 2713 BUG_ON(vma->vm_end < end);
7d8faaf155454f Zach O'Keefe 2022-07-06 2714
7d8faaf155454f Zach O'Keefe 2022-07-06 2715 *prev = vma;
7d8faaf155454f Zach O'Keefe 2022-07-06 2716
3485b88390b0af Ryan Roberts 2023-12-07 2717 if (!thp_vma_allowable_order(vma, vma->vm_flags, false, false, false,
3485b88390b0af Ryan Roberts 2023-12-07 2718 PMD_ORDER))
7d8faaf155454f Zach O'Keefe 2022-07-06 2719 return -EINVAL;
7d8faaf155454f Zach O'Keefe 2022-07-06 2720
7d8faaf155454f Zach O'Keefe 2022-07-06 2721 cc = kmalloc(sizeof(*cc), GFP_KERNEL);
7d8faaf155454f Zach O'Keefe 2022-07-06 2722 if (!cc)
7d8faaf155454f Zach O'Keefe 2022-07-06 2723 return -ENOMEM;
7d8faaf155454f Zach O'Keefe 2022-07-06 2724 cc->is_khugepaged = false;
a37dacf95f1857 Lance Yang 2024-01-17 2725 cc->is_try = is_try;
7d8faaf155454f Zach O'Keefe 2022-07-06 2726
7d8faaf155454f Zach O'Keefe 2022-07-06 2727 mmgrab(mm);
7d8faaf155454f Zach O'Keefe 2022-07-06 2728 lru_add_drain_all();
7d8faaf155454f Zach O'Keefe 2022-07-06 2729
7d8faaf155454f Zach O'Keefe 2022-07-06 2730 hstart = (start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
7d8faaf155454f Zach O'Keefe 2022-07-06 2731 hend = end & HPAGE_PMD_MASK;
7d8faaf155454f Zach O'Keefe 2022-07-06 2732
7d8faaf155454f Zach O'Keefe 2022-07-06 2733 for (addr = hstart; addr < hend; addr += HPAGE_PMD_SIZE) {
7d8faaf155454f Zach O'Keefe 2022-07-06 2734 int result = SCAN_FAIL;
7d8faaf155454f Zach O'Keefe 2022-07-06 2735
7d8faaf155454f Zach O'Keefe 2022-07-06 2736 if (!mmap_locked) {
7d8faaf155454f Zach O'Keefe 2022-07-06 2737 cond_resched();
7d8faaf155454f Zach O'Keefe 2022-07-06 2738 mmap_read_lock(mm);
7d8faaf155454f Zach O'Keefe 2022-07-06 2739 mmap_locked = true;
34488399fa08fa Zach O'Keefe 2022-09-22 2740 result = hugepage_vma_revalidate(mm, addr, false, &vma,
34488399fa08fa Zach O'Keefe 2022-09-22 2741 cc);
7d8faaf155454f Zach O'Keefe 2022-07-06 2742 if (result != SCAN_SUCCEED) {
7d8faaf155454f Zach O'Keefe 2022-07-06 2743 last_fail = result;
7d8faaf155454f Zach O'Keefe 2022-07-06 2744 goto out_nolock;
7d8faaf155454f Zach O'Keefe 2022-07-06 2745 }
4d24de9425f75f Yang Shi 2022-09-14 2746
52dc031088f00e Zach O'Keefe 2022-12-24 2747 hend = min(hend, vma->vm_end & HPAGE_PMD_MASK);
7d8faaf155454f Zach O'Keefe 2022-07-06 2748 }
7d8faaf155454f Zach O'Keefe 2022-07-06 2749 mmap_assert_locked(mm);
7d8faaf155454f Zach O'Keefe 2022-07-06 2750 memset(cc->node_load, 0, sizeof(cc->node_load));
e031ff96b334a0 Yang Shi 2022-11-08 2751 nodes_clear(cc->alloc_nmask);
34488399fa08fa Zach O'Keefe 2022-09-22 2752 if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) {
34488399fa08fa Zach O'Keefe 2022-09-22 2753 struct file *file = get_file(vma->vm_file);
34488399fa08fa Zach O'Keefe 2022-09-22 2754 pgoff_t pgoff = linear_page_index(vma, addr);
34488399fa08fa Zach O'Keefe 2022-09-22 2755
34488399fa08fa Zach O'Keefe 2022-09-22 2756 mmap_read_unlock(mm);
34488399fa08fa Zach O'Keefe 2022-09-22 2757 mmap_locked = false;
34488399fa08fa Zach O'Keefe 2022-09-22 2758 result = hpage_collapse_scan_file(mm, addr, file, pgoff,
7d2c4385c3417c Zach O'Keefe 2022-07-06 2759 cc);
34488399fa08fa Zach O'Keefe 2022-09-22 2760 fput(file);
34488399fa08fa Zach O'Keefe 2022-09-22 2761 } else {
34488399fa08fa Zach O'Keefe 2022-09-22 2762 result = hpage_collapse_scan_pmd(mm, vma, addr,
34488399fa08fa Zach O'Keefe 2022-09-22 2763 &mmap_locked, cc);
34488399fa08fa Zach O'Keefe 2022-09-22 2764 }
7d8faaf155454f Zach O'Keefe 2022-07-06 2765 if (!mmap_locked)
7d8faaf155454f Zach O'Keefe 2022-07-06 2766 *prev = NULL; /* Tell caller we dropped mmap_lock */
7d8faaf155454f Zach O'Keefe 2022-07-06 2767
34488399fa08fa Zach O'Keefe 2022-09-22 2768 handle_result:
7d8faaf155454f Zach O'Keefe 2022-07-06 2769 switch (result) {
7d8faaf155454f Zach O'Keefe 2022-07-06 2770 case SCAN_SUCCEED:
7d8faaf155454f Zach O'Keefe 2022-07-06 2771 case SCAN_PMD_MAPPED:
7d8faaf155454f Zach O'Keefe 2022-07-06 2772 ++thps;
7d8faaf155454f Zach O'Keefe 2022-07-06 2773 break;
34488399fa08fa Zach O'Keefe 2022-09-22 2774 case SCAN_PTE_MAPPED_HUGEPAGE:
34488399fa08fa Zach O'Keefe 2022-09-22 2775 BUG_ON(mmap_locked);
34488399fa08fa Zach O'Keefe 2022-09-22 2776 BUG_ON(*prev);
1043173eb5eb35 Hugh Dickins 2023-07-11 2777 mmap_read_lock(mm);
34488399fa08fa Zach O'Keefe 2022-09-22 2778 result = collapse_pte_mapped_thp(mm, addr, true);
1043173eb5eb35 Hugh Dickins 2023-07-11 2779 mmap_read_unlock(mm);
34488399fa08fa Zach O'Keefe 2022-09-22 2780 goto handle_result;
a37dacf95f1857 Lance Yang 2024-01-17 2781 /* MADV_TRY_COLLAPSE: fail quickly */
a37dacf95f1857 Lance Yang 2024-01-17 2782 case SCAN_ALLOC_HUGE_PAGE_FAIL:
a37dacf95f1857 Lance Yang 2024-01-17 2783 case SCAN_CGROUP_CHARGE_FAIL:
a37dacf95f1857 Lance Yang 2024-01-17 2784 if (cc->is_try) {
a37dacf95f1857 Lance Yang 2024-01-17 2785 last_fail = result;
a37dacf95f1857 Lance Yang 2024-01-17 2786 goto out_maybelock;
a37dacf95f1857 Lance Yang 2024-01-17 2787 }
7d8faaf155454f Zach O'Keefe 2022-07-06 2788 /* Whitelisted set of results where continuing OK */
7d8faaf155454f Zach O'Keefe 2022-07-06 @2789 case SCAN_PMD_NULL:
--
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