Commit 54fa49b2 authored by Sidhartha Kumar's avatar Sidhartha Kumar Committed by Andrew Morton
Browse files

mm/hugetlb: convert dissolve_free_huge_pages() to folios 

Allows us to rename dissolve_free_huge_pages() to
dissolve_free_hugetlb_folio(). Convert one caller to pass in a folio
directly and use page_folio() to convert the caller in mm/memory-failure.

[sidhartha.kumar@oracle.com: remove unneeded `extern']
  Link: https://lkml.kernel.org/r/71760ed4-e80d-493a-95ea-2545414b1aba@oracle.com
[sidhartha.kumar@oracle.com: v2]
  Link: https://lkml.kernel.org/r/20240412182139.120871-1-sidhartha.kumar@oracle.com
Link: https://lkml.kernel.org/r/20240411164756.261178-1-sidhartha.kumar@oracle.com


Signed-off-by: default avatarSidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Reviewed-by: default avatarVishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 452e862f

include/linux/hugetlb.h

+2 −2
Original line number Diff line number Diff line
@@ -861,7 +861,7 @@ static inline int hstate_index(struct hstate *h) 
	return h - hstates;

}



extern int dissolve_free_huge_page(struct page *page);

int dissolve_free_hugetlb_folio(struct folio *folio);

extern int dissolve_free_huge_pages(unsigned long start_pfn,

				    unsigned long end_pfn);
@@ -1148,7 +1148,7 @@ static inline int hstate_index(struct hstate *h) 
	return 0;

}



static inline int dissolve_free_huge_page(struct page *page)

static inline int dissolve_free_hugetlb_folio(struct folio *folio)

{

	return 0;

}

mm/hugetlb.c

+8 −9
Original line number Diff line number Diff line
@@ -2377,8 +2377,8 @@ static struct folio *remove_pool_hugetlb_folio(struct hstate *h, 
}



/*

 * Dissolve a given free hugepage into free buddy pages. This function does

 * nothing for in-use hugepages and non-hugepages.

 * Dissolve a given free hugetlb folio into free buddy pages. This function

 * does nothing for in-use hugetlb folios and non-hugetlb folios.

 * This function returns values like below:

 *

 *  -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages
@@ -2390,10 +2390,9 @@ static struct folio *remove_pool_hugetlb_folio(struct hstate *h, 
 *       0:  successfully dissolved free hugepages or the page is not a

 *           hugepage (considered as already dissolved)

 */

int dissolve_free_huge_page(struct page *page)

int dissolve_free_hugetlb_folio(struct folio *folio)

{

	int rc = -EBUSY;

	struct folio *folio = page_folio(page);



retry:

	/* Not to disrupt normal path by vainly holding hugetlb_lock */
@@ -2470,13 +2469,13 @@ int dissolve_free_huge_page(struct page *page) 
 * make specified memory blocks removable from the system.

 * Note that this will dissolve a free gigantic hugepage completely, if any

 * part of it lies within the given range.

 * Also note that if dissolve_free_huge_page() returns with an error, all

 * free hugepages that were dissolved before that error are lost.

 * Also note that if dissolve_free_hugetlb_folio() returns with an error, all

 * free hugetlb folios that were dissolved before that error are lost.

 */

int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)

{

	unsigned long pfn;

	struct page *page;

	struct folio *folio;

	int rc = 0;

	unsigned int order;

	struct hstate *h;
@@ -2489,8 +2488,8 @@ int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 
		order = min(order, huge_page_order(h));



	for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) {

		page = pfn_to_page(pfn);

		rc = dissolve_free_huge_page(page);

		folio = pfn_folio(pfn);

		rc = dissolve_free_hugetlb_folio(folio);

		if (rc)

			break;

	}

mm/memory-failure.c

+4 −4
Original line number Diff line number Diff line
@@ -155,7 +155,7 @@ static int __page_handle_poison(struct page *page) 


	/*

	 * zone_pcp_disable() can't be used here. It will

	 * hold pcp_batch_high_lock and dissolve_free_huge_page() might hold

	 * hold pcp_batch_high_lock and dissolve_free_hugetlb_folio() might hold

	 * cpu_hotplug_lock via static_key_slow_dec() when hugetlb vmemmap

	 * optimization is enabled. This will break current lock dependency

	 * chain and leads to deadlock.
@@ -165,7 +165,7 @@ static int __page_handle_poison(struct page *page) 
	 * but nothing guarantees that those pages do not get back to a PCP

	 * queue if we need to refill those.

	 */

	ret = dissolve_free_huge_page(page);

	ret = dissolve_free_hugetlb_folio(page_folio(page));

	if (!ret) {

		drain_all_pages(page_zone(page));

		ret = take_page_off_buddy(page);
@@ -178,8 +178,8 @@ static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, boo 
{

	if (hugepage_or_freepage) {

		/*

		 * Doing this check for free pages is also fine since dissolve_free_huge_page

		 * returns 0 for non-hugetlb pages as well.

		 * Doing this check for free pages is also fine since

		 * dissolve_free_hugetlb_folio() returns 0 for non-hugetlb folios as well.

		 */

		if (__page_handle_poison(page) <= 0)

			/*