On Wed, Jun 22, 2022 at 04:58:54PM +0800, Baolin Wang wrote:
> Now the kernel PTE level ptes are always protected by mm->page_table_lock
> instead of split pagetable lock, so the kernel PTE level pagetable pages
> are not accounted. Especially the vmalloc()/vmap() can consume lots of
> kernel pagetable, so to get an accurate pagetable accounting, calling new
> helpers pgtable_set_and_inc()/pgtable_clear_and_dec() when allocating or
> freeing a kernel PTE level pagetable page.
This patch only adds accounting to the page tables allocated after boot,
please mention this in the changelog.
> Meanwhile converting architectures to use corresponding generic PTE pagetable
> allocation and freeing functions.
>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> ---
> arch/csky/include/asm/pgalloc.h | 2 +-
> arch/microblaze/mm/pgtable.c | 2 +-
> arch/openrisc/mm/ioremap.c | 2 +-
> arch/x86/mm/pgtable.c | 5 ++++-
> include/asm-generic/pgalloc.h | 14 ++++++++++++--
> 5 files changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/arch/csky/include/asm/pgalloc.h b/arch/csky/include/asm/pgalloc.h
> index bbbd069..2443226 100644
> --- a/arch/csky/include/asm/pgalloc.h
> +++ b/arch/csky/include/asm/pgalloc.h
> @@ -29,7 +29,7 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> pte_t *pte;
> unsigned long i;
>
> - pte = (pte_t *) __get_free_page(GFP_KERNEL);
> + pte = __pte_alloc_one_kernel(mm);
> if (!pte)
> return NULL;
>
> diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c
> index 9f73265..e96dd1b 100644
> --- a/arch/microblaze/mm/pgtable.c
> +++ b/arch/microblaze/mm/pgtable.c
> @@ -245,7 +245,7 @@ unsigned long iopa(unsigned long addr)
> __ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> {
> if (mem_init_done)
> - return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
> + return __pte_alloc_one_kernel(mm);
> else
> return memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE,
> MEMBLOCK_LOW_LIMIT,
> diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
> index daae13a..3453acc 100644
> --- a/arch/openrisc/mm/ioremap.c
> +++ b/arch/openrisc/mm/ioremap.c
> @@ -118,7 +118,7 @@ pte_t __ref *pte_alloc_one_kernel(struct mm_struct *mm)
> pte_t *pte;
>
> if (likely(mem_init_done)) {
> - pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
> + pte = __pte_alloc_one_kernel(mm);
> } else {
> pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> if (!pte)
> diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
> index a8ab3f9..fc2b9ef 100644
> --- a/arch/x86/mm/pgtable.c
> +++ b/arch/x86/mm/pgtable.c
> @@ -851,6 +851,7 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr)
> int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
> {
> pte_t *pte;
> + struct page *page;
>
> pte = (pte_t *)pmd_page_vaddr(*pmd);
> pmd_clear(pmd);
> @@ -858,7 +859,9 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
> /* INVLPG to clear all paging-structure caches */
> flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1);
>
> - free_page((unsigned long)pte);
> + page = virt_to_page(pte);
> + pgtable_clear_and_dec(page);
> + __free_page(page);
>
> return 1;
> }
> diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
> index 328a714..2e20e9e 100644
> --- a/include/asm-generic/pgalloc.h
> +++ b/include/asm-generic/pgalloc.h
> @@ -18,7 +18,14 @@
> */
> static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm)
> {
> - return (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL);
> + struct page *page;
> + gfp_t gfp = GFP_PGTABLE_KERNEL;
> +
> + page = alloc_pages(gfp & ~__GFP_HIGHMEM, 0);
> + if (!page)
> + return NULL;
> + pgtable_set_and_inc(page);
> + return (pte_t *)page_address(page);
{
pte_t *pte = (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL);
if (pte)
pgtable_set_and_inc(virt_to_page(pte));
return pte;
}
looks simpler, doesn't it?
> }
>
> #ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
> @@ -41,7 +48,10 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> */
> static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> {
> - free_page((unsigned long)pte);
> + struct page *page = virt_to_page(pte);
> +
> + pgtable_clear_and_dec(page);
> + __free_page(page);
> }
>
> /**
> --
> 1.8.3.1
>
--
Sincerely yours,
Mike.
