linux-kernel - Re: [PATCH 07/13] s390: make setup_zero

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Message-ID: <20250307152815.9880Gbd-hca@linux.ibm.com>
Date: Fri, 7 Mar 2025 16:28:15 +0100
From: Heiko Carstens <hca@...ux.ibm.com>
To: Mike Rapoport <rppt@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
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Subject: Re: [PATCH 07/13] s390: make setup_zero_pages() use memblock

On Thu, Mar 06, 2025 at 08:51:17PM +0200, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@...nel.org>
> 
> Allocating the zero pages from memblock is simpler because the memory is
> already reserved.
> 
> This will also help with pulling out memblock_free_all() to the generic
> code and reducing code duplication in arch::mem_init().
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@...nel.org>
> ---
>  arch/s390/mm/init.c | 14 +++-----------
>  1 file changed, 3 insertions(+), 11 deletions(-)

Acked-by: Heiko Carstens <hca@...ux.ibm.com>

> -	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
> +	empty_zero_page = (unsigned long)memblock_alloc(PAGE_SIZE << order, order);
>  	if (!empty_zero_page)
>  		panic("Out of memory in setup_zero_pages");

This could have been converted to memblock_alloc_or_panic(), but I
guess this can also be done at a later point in time.