Re: [PATCH 11/12] mm: pgtable: introduce generic __tlb_remove_table()
From: Peter Zijlstra
Date: Mon Dec 16 2024 - 13:15:21 EST
On Mon, Dec 16, 2024 at 08:52:06PM +0800, Qi Zheng wrote:
>
>
> On 2024/12/16 20:00, Peter Zijlstra wrote:
> > On Sat, Dec 14, 2024 at 05:02:57PM +0800, Qi Zheng wrote:
>
> [...]
>
> > > +#ifndef __HAVE_ARCH_TLB_REMOVE_TABLE
> > > +static inline void __tlb_remove_table(void *_table)
> > > +{
> > > + struct ptdesc *ptdesc = (struct ptdesc *)_table;
> > > +
> > > + pagetable_dtor(ptdesc);
> > > + pagetable_free(ptdesc);
> > > +}
> > > +#endif
> >
> >
> > Spot the fail...
> >
> > That said, all this ptdesc stuff is another giant trainwreck. Let me
> > clean that up for you.
>
> It looks like you want to revert what was done in this patch series:
>
> https://lore.kernel.org/all/20230807230513.102486-1-vishal.moola@xxxxxxxxx/
>
> But why? It seems that splitting ptdesc from struct page is a good
> thing?
Because we're explicitly allocating pages for the page-tables, and also,
code like:
tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));
static inline void tlb_remove_page_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt)
{
tlb_remove_page(tlb, ptdesc_page(pt));
}
Just makes me upset.
Just bloody write tlb_remove_page() and call it a day.
All that nonsense is just obfuscation at this point.