Re: [PATCH v5 06/17] s390: pgtable: add statistics for PUD and P4D level page table

[Alexander Gordeev]

On Wed, Jan 08, 2025 at 02:57:22PM +0800, Qi Zheng wrote:
> Like PMD and PTE level page table, also add statistics for PUD and P4D
> page table.
> 
> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> Suggested-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Reviewed-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
> Cc: linux-s390@xxxxxxxxxxxxxxx
> ---
>  arch/s390/include/asm/pgalloc.h | 29 +++++++++++++++++++++--------
>  arch/s390/include/asm/tlb.h     |  2 ++
>  2 files changed, 23 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
> index 7b84ef6dc4b6d..a0c1ca5d8423c 100644
> --- a/arch/s390/include/asm/pgalloc.h
> +++ b/arch/s390/include/asm/pgalloc.h
> @@ -53,29 +53,42 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long address)
>  {
>  	unsigned long *table = crst_table_alloc(mm);
>  
> -	if (table)
> -		crst_table_init(table, _REGION2_ENTRY_EMPTY);
> +	if (!table)
> +		return NULL;
> +	crst_table_init(table, _REGION2_ENTRY_EMPTY);
> +	pagetable_p4d_ctor(virt_to_ptdesc(table));
> +
>  	return (p4d_t *) table;
>  }
>  
>  static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
>  {
> -	if (!mm_p4d_folded(mm))
> -		crst_table_free(mm, (unsigned long *) p4d);
> +	if (mm_p4d_folded(mm))
> +		return;
> +
> +	pagetable_p4d_dtor(virt_to_ptdesc(p4d));
> +	crst_table_free(mm, (unsigned long *) p4d);
>  }
>  
>  static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
>  {
>  	unsigned long *table = crst_table_alloc(mm);
> -	if (table)
> -		crst_table_init(table, _REGION3_ENTRY_EMPTY);
> +
> +	if (!table)
> +		return NULL;
> +	crst_table_init(table, _REGION3_ENTRY_EMPTY);
> +	pagetable_pud_ctor(virt_to_ptdesc(table));
> +
>  	return (pud_t *) table;
>  }
>  
>  static inline void pud_free(struct mm_struct *mm, pud_t *pud)
>  {
> -	if (!mm_pud_folded(mm))
> -		crst_table_free(mm, (unsigned long *) pud);
> +	if (mm_pud_folded(mm))
> +		return;
> +
> +	pagetable_pud_dtor(virt_to_ptdesc(pud));
> +	crst_table_free(mm, (unsigned long *) pud);
>  }
>  
>  static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
> diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
> index e95b2c8081eb8..907d57a68145c 100644
> --- a/arch/s390/include/asm/tlb.h
> +++ b/arch/s390/include/asm/tlb.h
> @@ -122,6 +122,7 @@ static inline void p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
>  {
>  	if (mm_p4d_folded(tlb->mm))
>  		return;
> +	pagetable_p4d_dtor(virt_to_ptdesc(p4d));
>  	__tlb_adjust_range(tlb, address, PAGE_SIZE);
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
> @@ -140,6 +141,7 @@ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
>  {
>  	if (mm_pud_folded(tlb->mm))
>  		return;
> +	pagetable_pud_dtor(virt_to_ptdesc(pud));
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
>  	tlb->cleared_p4ds = 1;

Acked-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>

Thanks!