+ mm-migration-return-errno-when-isolate_huge_page-failed.patch added to mm-unstable branch

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: mm/migration: return errno when isolate_huge_page failed
has been added to the -mm mm-unstable branch.  Its filename is
     mm-migration-return-errno-when-isolate_huge_page-failed.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-migration-return-errno-when-isolate_huge_page-failed.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/migration: return errno when isolate_huge_page failed
Date: Mon, 30 May 2022 19:30:15 +0800

We might fail to isolate huge page due to e.g.  the page is under
migration which cleared HPageMigratable.  We should return errno in this
case rather than always return 1 which could confuse the user, i.e.  the
caller might think all of the memory is migrated while the hugetlb page is
left behind.  We make the prototype of isolate_huge_page consistent with
isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page
to isolate_hugetlb as suggested by Muchun to improve the readability.

Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@xxxxxxxxxx
Fixes: e8db67eb0ded ("mm: migrate: move_pages() supports thp migration")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Suggested-by: Huang Ying <ying.huang@xxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx> (build error)
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 include/linux/hugetlb.h |    6 +++---
 mm/gup.c                |    2 +-
 mm/hugetlb.c            |   11 +++++------
 mm/memory-failure.c     |    2 +-
 mm/memory_hotplug.c     |    2 +-
 mm/mempolicy.c          |    2 +-
 mm/migrate.c            |    7 ++++---
 7 files changed, 16 insertions(+), 16 deletions(-)

--- a/include/linux/hugetlb.h~mm-migration-return-errno-when-isolate_huge_page-failed
+++ a/include/linux/hugetlb.h
@@ -170,7 +170,7 @@ bool hugetlb_reserve_pages(struct inode
 						vm_flags_t vm_flags);
 long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
 						long freed);
-bool isolate_huge_page(struct page *page, struct list_head *list);
+int isolate_hugetlb(struct page *page, struct list_head *list);
 int get_hwpoison_huge_page(struct page *page, bool *hugetlb);
 int get_huge_page_for_hwpoison(unsigned long pfn, int flags);
 void putback_active_hugepage(struct page *page);
@@ -376,9 +376,9 @@ static inline pte_t *huge_pte_offset(str
 	return NULL;
 }
 
-static inline bool isolate_huge_page(struct page *page, struct list_head *list)
+static inline int isolate_hugetlb(struct page *page, struct list_head *list)
 {
-	return false;
+	return -EBUSY;
 }
 
 static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb)
--- a/mm/gup.c~mm-migration-return-errno-when-isolate_huge_page-failed
+++ a/mm/gup.c
@@ -1930,7 +1930,7 @@ static long check_and_migrate_movable_pa
 		 * Try to move out any movable page before pinning the range.
 		 */
 		if (folio_test_hugetlb(folio)) {
-			if (!isolate_huge_page(&folio->page,
+			if (isolate_hugetlb(&folio->page,
 						&movable_page_list))
 				isolation_error_count++;
 			continue;
--- a/mm/hugetlb.c~mm-migration-return-errno-when-isolate_huge_page-failed
+++ a/mm/hugetlb.c
@@ -2765,8 +2765,7 @@ retry:
 		 * Fail with -EBUSY if not possible.
 		 */
 		spin_unlock_irq(&hugetlb_lock);
-		if (!isolate_huge_page(old_page, list))
-			ret = -EBUSY;
+		ret = isolate_hugetlb(old_page, list);
 		spin_lock_irq(&hugetlb_lock);
 		goto free_new;
 	} else if (!HPageFreed(old_page)) {
@@ -2842,7 +2841,7 @@ int isolate_or_dissolve_huge_page(struct
 	if (hstate_is_gigantic(h))
 		return -ENOMEM;
 
-	if (page_count(head) && isolate_huge_page(head, list))
+	if (page_count(head) && !isolate_hugetlb(head, list))
 		ret = 0;
 	else if (!page_count(head))
 		ret = alloc_and_dissolve_huge_page(h, head, list);
@@ -6952,15 +6951,15 @@ follow_huge_pgd(struct mm_struct *mm, un
 	return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT);
 }
 
-bool isolate_huge_page(struct page *page, struct list_head *list)
+int isolate_hugetlb(struct page *page, struct list_head *list)
 {
-	bool ret = true;
+	int ret = 0;
 
 	spin_lock_irq(&hugetlb_lock);
 	if (!PageHeadHuge(page) ||
 	    !HPageMigratable(page) ||
 	    !get_page_unless_zero(page)) {
-		ret = false;
+		ret = -EBUSY;
 		goto unlock;
 	}
 	ClearHPageMigratable(page);
--- a/mm/memory-failure.c~mm-migration-return-errno-when-isolate_huge_page-failed
+++ a/mm/memory-failure.c
@@ -2166,7 +2166,7 @@ static bool isolate_page(struct page *pa
 	bool lru = PageLRU(page);
 
 	if (PageHuge(page)) {
-		isolated = isolate_huge_page(page, pagelist);
+		isolated = !isolate_hugetlb(page, pagelist);
 	} else {
 		if (lru)
 			isolated = !isolate_lru_page(page);
--- a/mm/memory_hotplug.c~mm-migration-return-errno-when-isolate_huge_page-failed
+++ a/mm/memory_hotplug.c
@@ -1643,7 +1643,7 @@ do_migrate_range(unsigned long start_pfn
 
 		if (PageHuge(page)) {
 			pfn = page_to_pfn(head) + compound_nr(head) - 1;
-			isolate_huge_page(head, &source);
+			isolate_hugetlb(head, &source);
 			continue;
 		} else if (PageTransHuge(page))
 			pfn = page_to_pfn(head) + thp_nr_pages(page) - 1;
--- a/mm/mempolicy.c~mm-migration-return-errno-when-isolate_huge_page-failed
+++ a/mm/mempolicy.c
@@ -602,7 +602,7 @@ static int queue_pages_hugetlb(pte_t *pt
 	/* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
 	if (flags & (MPOL_MF_MOVE_ALL) ||
 	    (flags & MPOL_MF_MOVE && page_mapcount(page) == 1)) {
-		if (!isolate_huge_page(page, qp->pagelist) &&
+		if (isolate_hugetlb(page, qp->pagelist) &&
 			(flags & MPOL_MF_STRICT))
 			/*
 			 * Failed to isolate page but allow migrating pages
--- a/mm/migrate.c~mm-migration-return-errno-when-isolate_huge_page-failed
+++ a/mm/migrate.c
@@ -133,7 +133,7 @@ static void putback_movable_page(struct
  *
  * This function shall be used whenever the isolated pageset has been
  * built from lru, balloon, hugetlbfs page. See isolate_migratepages_range()
- * and isolate_huge_page().
+ * and isolate_hugetlb().
  */
 void putback_movable_pages(struct list_head *l)
 {
@@ -1627,8 +1627,9 @@ static int add_page_for_migration(struct
 
 	if (PageHuge(page)) {
 		if (PageHead(page)) {
-			isolate_huge_page(page, pagelist);
-			err = 1;
+			err = isolate_hugetlb(page, pagelist);
+			if (!err)
+				err = 1;
 		}
 	} else {
 		struct page *head;
_

Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are

maintainers-add-maintainer-information-for-z3fold.patch
mm-shmemc-clean-up-comment-of-shmem_swapin_folio.patch
mm-reduce-the-rcu-lock-duration.patch
mm-migration-remove-unneeded-lock-page-and-pagemovable-check.patch
mm-migration-return-errno-when-isolate_huge_page-failed.patch
mm-migration-fix-potential-pte_unmap-on-an-not-mapped-pte.patch




[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux