Commit 972b89c1 authored by Wei Yang's avatar Wei Yang Committed by Andrew Morton
Browse files

mm/mm_init.c: simplify logic of deferred_[init|free]_pages 

Function deferred_[init|free]_pages are only used in
deferred_init_maxorder(), which makes sure the range to init/free is
within MAX_ORDER_NR_PAGES size.

With this knowledge, we can simplify these two functions. Since

  * only the first pfn could be IS_MAX_ORDER_ALIGNED()

Also since the range passed to deferred_[init|free]_pages is always from
memblock.memory for those we have already allocated memmap to cover,
pfn_valid() always return true.  Then we can remove related check.

[richard.weiyang@gmail.com: adjust function declaration indention per David]
  Link: https://lkml.kernel.org/r/20240613114525.27528-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20240612020421.31975-1-richard.weiyang@gmail.com


Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
Reviewed-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e5d89670

mm/mm_init.c

+8 −56
Original line number Diff line number Diff line
@@ -1916,7 +1916,7 @@ unsigned long __init node_map_pfn_alignment(void) 
}



#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT

static void __init deferred_free_range(unsigned long pfn,

static void __init deferred_free_pages(unsigned long pfn,

		unsigned long nr_pages)

{

	struct page *page;
@@ -1955,69 +1955,21 @@ static inline void __init pgdat_init_report_one_done(void) 
		complete(&pgdat_init_all_done_comp);

}



/*

 * Returns true if page needs to be initialized or freed to buddy allocator.

 *

 * We check if a current MAX_PAGE_ORDER block is valid by only checking the

 * validity of the head pfn.

 */

static inline bool __init deferred_pfn_valid(unsigned long pfn)

{

	if (IS_MAX_ORDER_ALIGNED(pfn) && !pfn_valid(pfn))

		return false;

	return true;

}



/*

 * Free pages to buddy allocator. Try to free aligned pages in

 * MAX_ORDER_NR_PAGES sizes.

 */

static void __init deferred_free_pages(unsigned long pfn,

				       unsigned long end_pfn)

{

	unsigned long nr_free = 0;



	for (; pfn < end_pfn; pfn++) {

		if (!deferred_pfn_valid(pfn)) {

			deferred_free_range(pfn - nr_free, nr_free);

			nr_free = 0;

		} else if (IS_MAX_ORDER_ALIGNED(pfn)) {

			deferred_free_range(pfn - nr_free, nr_free);

			nr_free = 1;

		} else {

			nr_free++;

		}

	}

	/* Free the last block of pages to allocator */

	deferred_free_range(pfn - nr_free, nr_free);

}



/*

 * Initialize struct pages.  We minimize pfn page lookups and scheduler checks

 * by performing it only once every MAX_ORDER_NR_PAGES.

 * Return number of pages initialized.

 */

static unsigned long __init deferred_init_pages(struct zone *zone,

						 unsigned long pfn,

						 unsigned long end_pfn)

		unsigned long pfn, unsigned long end_pfn)

{

	int nid = zone_to_nid(zone);

	unsigned long nr_pages = 0;

	unsigned long nr_pages = end_pfn - pfn;

	int zid = zone_idx(zone);

	struct page *page = NULL;

	struct page *page = pfn_to_page(pfn);



	for (; pfn < end_pfn; pfn++) {

		if (!deferred_pfn_valid(pfn)) {

			page = NULL;

			continue;

		} else if (!page || IS_MAX_ORDER_ALIGNED(pfn)) {

			page = pfn_to_page(pfn);

		} else {

			page++;

		}

	for (; pfn < end_pfn; pfn++, page++)

		__init_single_page(page, pfn, zid, nid);

		nr_pages++;

	}

	return nr_pages;

}
@@ -2096,7 +2048,7 @@ deferred_init_maxorder(u64 *i, struct zone *zone, unsigned long *start_pfn, 
			break;



		t = min(mo_pfn, epfn);

		deferred_free_pages(spfn, t);

		deferred_free_pages(spfn, t - spfn);



		if (mo_pfn <= epfn)

			break;