Re: [PATCH 3/3] mm: Add kernel PTE level pagetable pages account

Matthew Wilcox
2022-07-06T15:50:38Z

On Wed, Jul 06, 2022 at 04:59:17PM +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 page_{set,clear}_pgtable() when allocating or freeing a kernel
> PTE level pagetable page.
>
> Meanwhile converting architectures to use corresponding generic PTE pagetable
> allocation and freeing functions.
>
> Note this patch only adds accounting to the page tables allocated after boot.
>
> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Reported-by: kernel test robot <oliver.sang@intel.com>

What does this Reported-by: even mean? the kernel test robot told you
that the page tables weren't being accounted?

I don't understand why we want to start accounting kernel page tables.
an we have a *discussion* about that with a sensible thread name instead
of just trying to sneak it in as patch 3/3?