2019-05-30 11:11:37

by William Kucharski

Subject: Re: [PATCH uprobe, thp 3/4] uprobe: support huge page by only splitting the pmd

Is there any reason to worry about supporting PUD-sized uprobe pages if
CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD is defined? I would prefer
not to bake in the assumption that "huge" means PMD-sized and more than
it already is.

For example, if CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD is configured,
mm_address_trans_huge() should either make the call to pud_trans_huge()
if appropriate, or a VM_BUG_ON_PAGE should be added in case the routine
is ever called with one.

Otherwise it looks pretty reasonable to me.

-- Bill

2019-05-30 17:27:28

by Song Liu

Subject: Re: [PATCH uprobe, thp 3/4] uprobe: support huge page by only splitting the pmd

> On May 30, 2019, at 4:08 AM, William Kucharski <[email protected]> wrote:
>
>
> Is there any reason to worry about supporting PUD-sized uprobe pages if
> CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD is defined? I would prefer
> not to bake in the assumption that "huge" means PMD-sized and more than
> it already is.
>
> For example, if CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD is configured,
> mm_address_trans_huge() should either make the call to pud_trans_huge()
> if appropriate, or a VM_BUG_ON_PAGE should be added in case the routine
> is ever called with one.
>
> Otherwise it looks pretty reasonable to me.
>
> -- Bill
>

I will try that in v2.

Thanks,
Song