Commit b62b51d2 authored by Kefeng Wang's avatar Kefeng Wang Committed by Andrew Morton
Browse files

mm: memory_hotplug: remove head variable in do_migrate_range() 

Patch series "mm: memory_hotplug: improve do_migrate_range()", v3.

Unify hwpoisoned page handling and isolation of HugeTLB/LRU/non-LRU
movable page, also convert to use folios in do_migrate_range().


This patch (of 5):

Directly use a folio for HugeTLB and THP when calculate the next pfn, then
remove unused head variable.

Link: https://lkml.kernel.org/r/20240827114728.3212578-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240827114728.3212578-2-wangkefeng.wang@huawei.com


Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f66ac836

mm/memory_hotplug.c

+14 −8
Original line number Diff line number Diff line
@@ -1773,7 +1773,7 @@ static int scan_movable_pages(unsigned long start, unsigned long end, 
static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)

{

	unsigned long pfn;

	struct page *page, *head;

	struct page *page;

	LIST_HEAD(source);

	static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL,

				      DEFAULT_RATELIMIT_BURST);
@@ -1786,14 +1786,20 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 
			continue;

		page = pfn_to_page(pfn);

		folio = page_folio(page);

		head = &folio->page;



		if (PageHuge(page)) {

			pfn = page_to_pfn(head) + compound_nr(head) - 1;

		/*

		 * No reference or lock is held on the folio, so it might

		 * be modified concurrently (e.g. split).  As such,

		 * folio_nr_pages() may read garbage.  This is fine as the outer

		 * loop will revisit the split folio later.

		 */

		if (folio_test_large(folio)) {

			pfn = folio_pfn(folio) + folio_nr_pages(folio) - 1;

			if (folio_test_hugetlb(folio)) {

				isolate_hugetlb(folio, &source);

				continue;

		} else if (PageTransHuge(page))

			pfn = page_to_pfn(head) + thp_nr_pages(page) - 1;

			}

		}



		/*

		 * HWPoison pages have elevated reference counts so the migration would