ACK: [SRU][B][PATCH 1/1] UBUNTU: SAUCE: Revert "x86/mm: Don't free P4D table when it is folded at runtime"

[Thadeu Lima de Souza Cascardo]

On Fri, Oct 08, 2021 at 12:00:33PM +0200, Krzysztof Kozlowski wrote:
> BugLink: https://bugs.launchpad.net/bugs/1946464
> 
> This reverts commit 5047ef5725ed1b31e405e1f1a90881e44d1f0816 (commit
> 0e311d237d7f3022b7dafb639b42541bfb42fe94 upstream) which
> should not be backported to v4.15:
> 
> 1. It adds pgtable_l5_enabled which does not exist in v4.15,
> 2. It is marked as v4.17+,
> 3. It is marked as fixing commit which does not exist in v4.15 and was
>    not backported there.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski at canonical.com>
> ---

Acked-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>

>  arch/x86/include/asm/pgalloc.h | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
> index 8df72517aafc..aff42e1da6ee 100644
> --- a/arch/x86/include/asm/pgalloc.h
> +++ b/arch/x86/include/asm/pgalloc.h
> @@ -182,9 +182,6 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
>  
>  static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
>  {
> -	if (!pgtable_l5_enabled)
> -		return;
> -
>  	BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
>  	free_page((unsigned long)p4d);
>  }
> -- 
> 2.30.2