Re: [PATCH 07/13] s390: make setup_zero_pages() use memblock

Mike Rapoport
2025-03-11T05:56:22Z

On Fri, Mar 07, 2025 at 04:28:15PM +0100, Heiko Carstens wrote:
> On Thu, Mar 06, 2025 at 08:51:17PM +0200, Mike Rapoport wrote:
> > From: "Mike Rapoport (Microsoft)" <rppt@kernel.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@kernel.org>
> > ---
> > arch/s390/mm/init.c | 14 +++-----------
> > 1 file changed, 3 insertions(+), 11 deletions(-)
>
> Acked-by: Heiko Carstens <hca@linux.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.

Duh, I should have remembered about memblock_alloc_or_panic() :)

@Andrew, can you please pick this as a fixup?

From 344fec8519e5152c25809c9277b54a68f9cde0e9 Mon Sep 17 00:00:00 2001
From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
Date: Tue, 11 Mar 2025 07:51:27 +0200
Subject: [PATCH] s390: use memblock_alloc_or_panic() in setup_zero_page()

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
arch/s390/mm/init.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index ab8ece3c41f1..c6a97329d7e7 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -81,9 +81,7 @@ static void __init setup_zero_pages(void)
while (order > 2 && (total_pages >> 10) < (1UL << order))
order--;

- empty_zero_page = (unsigned long)memblock_alloc(PAGE_SIZE << order, order);
- if (!empty_zero_page)
- panic("Out of memory in setup_zero_pages");
+ empty_zero_page = (unsigned long)memblock_alloc_or_panic(PAGE_SIZE << order, order);

zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
}
--
2.47.2

--
Sincerely yours,
Mike.