Re: [PATCH] arch/tile: support multiple huge page sizes dynamically

From: Hillf Danton
Date: Sat Mar 31 2012 - 08:09:30 EST


Hello Chris

On Sat, Mar 31, 2012 at 3:37 AM, Chris Metcalf <cmetcalf@xxxxxxxxxx> wrote:
> This change adds support for a new "super" bit in the tile PTE, and a
> new arch_make_huge_pte() method called from make_huge_pte().
> The Tilera hypervisor sees the bit set at a given level of the page
> table and gangs together 4, 16, or 64 consecutive pages from
> that level of the hierarchy to create a larger TLB entry.
>
> One extra "super" page size can be specified at each of the
> three levels of the page table hierarchy on tilegx, using the
> "hugepagesz" argument on the boot command line. ÂA new hypervisor
> API is added to allow Linux to tell the hypervisor how many PTEs
> to gang together at each level of the page table.
>
> To allow pre-allocating huge pages larger than the buddy allocator
> can handle, this change modifies the Tilera bootmem support to
> put all of memory on tilegx platforms into bootmem.
>
> As part of this change I eliminate the vestigial CONFIG_HIGHPTE
> support, which never worked anyway, and eliminate the hv_page_size()
> API in favor of the standard vma_kernel_pagesize() API.
>
> Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
> ---

[...]

> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index a876871..4531be2 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2123,6 +2123,9 @@ static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
> Â Â Â Â}
> Â Â Â Âentry = pte_mkyoung(entry);
> Â Â Â Âentry = pte_mkhuge(entry);
> +#ifdef arch_make_huge_pte
> + Â Â Â entry = arch_make_huge_pte(entry, vma, page, writable);
> +#endif
>
Would you please make arch_make_huge_pte() the way
that arch_prepare_hugepage() is implemented, or similar?

> Â Â Â Âreturn entry;
> Â}
> --
> 1.6.5.2
>
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