diff mbox series

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

Message ID 20250306185124.3147510-8-rppt@kernel.org (mailing list archive)
State New
Headers show
Series arch, mm: reduce code duplication in mem_init() | expand

Commit Message

Mike Rapoport March 6, 2025, 6:51 p.m. UTC
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(-)

Comments

Heiko Carstens March 7, 2025, 3:28 p.m. UTC | #1
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.
Mike Rapoport March 11, 2025, 5:55 a.m. UTC | #2
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;
 }
diff mbox series

Patch

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index f2298f7a3f21..020aa2f78d01 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -73,8 +73,6 @@  static void __init setup_zero_pages(void)
 {
 	unsigned long total_pages = memblock_estimated_nr_free_pages();
 	unsigned int order;
-	struct page *page;
-	int i;
 
 	/* Latest machines require a mapping granularity of 512KB */
 	order = 7;
@@ -83,17 +81,10 @@  static void __init setup_zero_pages(void)
 	while (order > 2 && (total_pages >> 10) < (1UL << order))
 		order--;
 
-	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");
 
-	page = virt_to_page((void *) empty_zero_page);
-	split_page(page, order);
-	for (i = 1 << order; i > 0; i--) {
-		mark_page_reserved(page);
-		page++;
-	}
-
 	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
 }
 
@@ -176,9 +167,10 @@  void __init mem_init(void)
 	pv_init();
 	kfence_split_mapping();
 
+	setup_zero_pages();	/* Setup zeroed pages. */
+
 	/* this will put all low memory onto the freelists */
 	memblock_free_all();
-	setup_zero_pages();	/* Setup zeroed pages. */
 }
 
 unsigned long memory_block_size_bytes(void)