Re: [PATCH v5 13/17] s390: pgtable: consolidate PxD and PTE TLB free paths

On Wed, Jan 08, 2025 at 02:57:29PM +0800, Qi Zheng wrote:
> Call pagetable_dtor() for PMD|PUD|P4D tables just before ptdesc is
> freed - same as it is done for PTE tables. That allows consolidating
> TLB free paths for all table types.
> 
> Signed-off-by: Qi Zheng <[email protected]>
> Suggested-by: Peter Zijlstra (Intel) <[email protected]>
> Reviewed-by: Kevin Brodsky <[email protected]>
> Cc: [email protected]
> ---
>  arch/s390/include/asm/tlb.h |  3 ---
>  arch/s390/mm/pgalloc.c      | 14 ++++----------
>  2 files changed, 4 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
> index dde847a5be545..d5b27a2445c96 100644
> --- a/arch/s390/include/asm/tlb.h
> +++ b/arch/s390/include/asm/tlb.h
> @@ -102,7 +102,6 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
>  {
>  	if (mm_pmd_folded(tlb->mm))
>  		return;
> -	pagetable_dtor(virt_to_ptdesc(pmd));
>  	__tlb_adjust_range(tlb, address, PAGE_SIZE);
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
> @@ -122,7 +121,6 @@ static inline void p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
>  {
>  	if (mm_p4d_folded(tlb->mm))
>  		return;
> -	pagetable_dtor(virt_to_ptdesc(p4d));
>  	__tlb_adjust_range(tlb, address, PAGE_SIZE);
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
> @@ -141,7 +139,6 @@ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
>  {
>  	if (mm_pud_folded(tlb->mm))
>  		return;
> -	pagetable_dtor(virt_to_ptdesc(pud));
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
>  	tlb->cleared_p4ds = 1;
> diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
> index 569de24d33761..c73b89811a264 100644
> --- a/arch/s390/mm/pgalloc.c
> +++ b/arch/s390/mm/pgalloc.c
> @@ -180,7 +180,7 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
>  	return table;
>  }
>  
> -static void pagetable_pte_dtor_free(struct ptdesc *ptdesc)
> +static void pagetable_dtor_free(struct ptdesc *ptdesc)
>  {
>  	pagetable_dtor(ptdesc);
>  	pagetable_free(ptdesc);
> @@ -190,20 +190,14 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
>  {
>  	struct ptdesc *ptdesc = virt_to_ptdesc(table);
>  
> -	pagetable_pte_dtor_free(ptdesc);
> +	pagetable_dtor_free(ptdesc);
>  }
>  
>  void __tlb_remove_table(void *table)
>  {
>  	struct ptdesc *ptdesc = virt_to_ptdesc(table);
> -	struct page *page = ptdesc_page(ptdesc);
>  
> -	if (compound_order(page) == CRST_ALLOC_ORDER) {
> -		/* pmd, pud, or p4d */
> -		pagetable_free(ptdesc);
> -		return;
> -	}
> -	pagetable_pte_dtor_free(ptdesc);
> +	pagetable_dtor_free(ptdesc);
>  }
>  
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> @@ -211,7 +205,7 @@ static void pte_free_now(struct rcu_head *head)
>  {
>  	struct ptdesc *ptdesc = container_of(head, struct ptdesc, pt_rcu_head);
>  
> -	pagetable_pte_dtor_free(ptdesc);
> +	pagetable_dtor_free(ptdesc);
>  }
>  
>  void pte_free_defer(struct mm_struct *mm, pgtable_t pgtable)

Acked-by: Alexander Gordeev <[email protected]>

Thanks!