On Thu, Dec 24, 2015 at 11:20:30AM -0500, Matthew Wilcox wrote:
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 4bf3811..e14634f 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1958,6 +1977,17 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
> return ptl;
> }
>
> +/*
> + * No scalability reason to split PUD locks yet, but follow the same pattern
> + * as the PMD locks to make it easier if we have to.
> + */
I don't think it makes any good unless you convert all other places where
we use page_table_lock to protect pud table (like __pud_alloc()) to the
same API.
I think this would deserve separate patch.
> +static inline spinlock_t *pud_lock(struct mm_struct *mm, pud_t *pud)
> +{
> + spinlock_t *ptl = &mm->page_table_lock;
> + spin_lock(ptl);
> + return ptl;
> +}
> +
> extern void free_area_init(unsigned long * zones_size);
> extern void free_area_init_node(int nid, unsigned long * zones_size,
> unsigned long zone_start_pfn, unsigned long *zholes_size);
...
> diff --git a/mm/memory.c b/mm/memory.c
> index 416b129..7328df0 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1220,9 +1220,27 @@ static inline unsigned long zap_pud_range(struct mmu_gather *tlb,
> pud = pud_offset(pgd, addr);
> do {
> next = pud_addr_end(addr, end);
> + if (pud_trans_huge(*pud) || pud_devmap(*pud)) {
> + if (next - addr != HPAGE_PUD_SIZE) {
> +#ifdef CONFIG_DEBUG_VM
IS_ENABLED(CONFIG_DEBUG_VM) ?
> + if (!rwsem_is_locked(&tlb->mm->mmap_sem)) {
> + pr_err("%s: mmap_sem is unlocked! addr=0x%lx end=0x%lx vma->vm_start=0x%lx vma->vm_end=0x%lx\n",
> + __func__, addr, end,
> + vma->vm_start,
> + vma->vm_end);
dump_vma(), I guess.
> + BUG();
> + }
> +#endif
> + split_huge_pud(vma, pud, addr);
> + } else if (zap_huge_pud(tlb, vma, pud, addr))
> + goto next;
> + /* fall through */
> + }
> if (pud_none_or_clear_bad(pud))
> continue;
> next = zap_pmd_range(tlb, vma, pud, addr, next, details);
> +next:
> + cond_resched();
> } while (pud++, addr = next, addr != end);
>
> return addr;
--
Kirill A. Shutemov
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