Re: [PATCH v2 11/15] mm: pgtable: introduce generic __tlb_remove_table()

[Qi Zheng]

On 2024/12/20 19:18, Alexander Gordeev wrote:
> On Wed, Dec 18, 2024 at 09:04:47PM +0800, Qi Zheng wrote:
> > Several architectures (arm, arm64, riscv, s390 and x86) define exactly the
> > same __tlb_remove_table(), just introduce generic __tlb_remove_table() to
> > eliminate these duplications.
>
> s390 is nearly the same, but not exactly (see below).
>
> >   arch/s390/include/asm/tlb.h     |  1 -
> >   arch/s390/mm/pgalloc.c          |  7 -------
> ...
> > --- a/arch/s390/mm/pgalloc.c
> > +++ b/arch/s390/mm/pgalloc.c
> > @@ -193,13 +193,6 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
> >   	pagetable_dtor_free(ptdesc);
> >   }
> >   
> > -void __tlb_remove_table(void *table)
> > -{
> > -	struct ptdesc *ptdesc = virt_to_ptdesc(table);
> > -
> > -	pagetable_dtor_free(ptdesc);
>
> With this change you introduce these duplication in __tlb_remove_table()
> and in pagetable_dtor_free():
>
> 	pagetable_dtor(ptdesc);
> 	pagetable_free(ptdesc);
>
> But I still would prefer to avoid __HAVE_ARCH_TLB_REMOVE_TABLE.
> Could it be possible to move pagetable_dtor_free() to asm-generic and
> make s390 __tlb_remove_table() version generic?

Yes, see my reply to Peter below:

https://lore.kernel.org/lkml/3f9a5475-930d-4f45-8fc8-8d2e8a6a08cc@xxxxxxxxxxxxx/

I will do it in v3. And I have make pagetable_dtor_free() generic in 
[PATCH v2 15/15].

> > -}
> > -
> >   #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> >   static void pte_free_now(struct rcu_head *head)
> >   {
>
> Thanks!