[PATCH v2 2/6] mm/mm_init.c: remove the useless dma_reserve

Baoquan He
2024-03-25T14:57:33Z

Now nobody calls set_dma_reserve() to set value for dma_reserve, remove
set_dma_reserve(), global variable dma_reserve and the codes using it.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
include/linux/mm.h | 1 -
mm/mm_init.c | 23 -----------------------
2 files changed, 24 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0436b919f1c7..ad19350e1538 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3210,7 +3210,6 @@ static inline int early_pfn_to_nid(unsigned long pfn)
extern int __meminit early_pfn_to_nid(unsigned long pfn);
#endif

-extern void set_dma_reserve(unsigned long new_dma_reserve);
extern void mem_init(void);
extern void __init mmap_init(void);

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 549e76af8f82..153fb2dc666f 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -226,7 +226,6 @@ static unsigned long required_movablecore_percent __initdata;

static unsigned long nr_kernel_pages __initdata;
static unsigned long nr_all_pages __initdata;
-static unsigned long dma_reserve __initdata;

static bool deferred_struct_pages __meminitdata;

@@ -1583,12 +1582,6 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
zone_names[j], memmap_pages, freesize);
}

- /* Account for reserved pages */
- if (j == 0 && freesize > dma_reserve) {
- freesize -= dma_reserve;
- pr_debug(" %s zone: %lu pages reserved\n", zone_names[0], dma_reserve);
- }
-
if (!is_highmem_idx(j))
nr_kernel_pages += freesize;
/* Charge for highmem memmap if there are enough kernel pages */
@@ -2547,22 +2540,6 @@ void *__init alloc_large_system_hash(const char *tablename,
return table;
}

-/**
- * set_dma_reserve - set the specified number of pages reserved in the first zone
- * @new_dma_reserve: The number of pages to mark reserved
- *
- * The per-cpu batchsize and zone watermarks are determined by managed_pages.
- * In the DMA zone, a significant percentage may be consumed by kernel image
- * and other unfreeable allocations which can skew the watermarks badly. This
- * function may optionally be used to account for unfreeable pages in the
- * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
- * smaller per-cpu batchsize.
- */
-void __init set_dma_reserve(unsigned long new_dma_reserve)
-{
- dma_reserve = new_dma_reserve;
-}
-
void __init memblock_free_pages(struct page *page, unsigned long pfn,
unsigned int order)
{
--
2.41.0