The patch titled
Subject: mm: hugetlb: change to return bool for isolate_hugetlb()
has been added to the -mm mm-unstable branch. Its filename is
mm-hugetlb-change-to-return-bool-for-isolate_hugetlb.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-change-to-return-bool-for-isolate_hugetlb.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Subject: mm: hugetlb: change to return bool for isolate_hugetlb()
Date: Wed, 15 Feb 2023 18:39:36 +0800
Now the isolate_hugetlb() only returns 0 or -EBUSY, and most users did not
care about the negative value, thus we can convert the isolate_hugetlb()
to return a boolean value to make code more clear when checking the
hugetlb isolation state. Moreover converts 2 users which will consider
the negative value returned by isolate_hugetlb().
No functional changes intended.
Link: https://lkml.kernel.org/r/12a287c5bebc13df304387087bbecc6421510849.1676424378.git.baolin.wang@xxxxxxxxxxxxxxxxx
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Acked-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 6 +++---
mm/hugetlb.c | 13 ++++++++-----
mm/memory-failure.c | 2 +-
mm/mempolicy.c | 2 +-
mm/migrate.c | 7 +++----
5 files changed, 16 insertions(+), 14 deletions(-)
--- a/include/linux/hugetlb.h~mm-hugetlb-change-to-return-bool-for-isolate_hugetlb
+++ a/include/linux/hugetlb.h
@@ -171,7 +171,7 @@ bool hugetlb_reserve_pages(struct inode
vm_flags_t vm_flags);
long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
long freed);
-int isolate_hugetlb(struct folio *folio, struct list_head *list);
+bool isolate_hugetlb(struct folio *folio, struct list_head *list);
int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison);
int get_huge_page_for_hwpoison(unsigned long pfn, int flags,
bool *migratable_cleared);
@@ -413,9 +413,9 @@ static inline pte_t *huge_pte_offset(str
return NULL;
}
-static inline int isolate_hugetlb(struct folio *folio, struct list_head *list)
+static inline bool isolate_hugetlb(struct folio *folio, struct list_head *list)
{
- return -EBUSY;
+ return false;
}
static inline int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison)
--- a/mm/hugetlb.c~mm-hugetlb-change-to-return-bool-for-isolate_hugetlb
+++ a/mm/hugetlb.c
@@ -2925,13 +2925,16 @@ retry:
*/
goto free_new;
} else if (folio_ref_count(old_folio)) {
+ bool isolated;
+
/*
* Someone has grabbed the folio, try to isolate it here.
* Fail with -EBUSY if not possible.
*/
spin_unlock_irq(&hugetlb_lock);
- ret = isolate_hugetlb(old_folio, list);
+ isolated = isolate_hugetlb(old_folio, list);
spin_lock_irq(&hugetlb_lock);
+ ret = isolated ? 0 : -EBUSY;
goto free_new;
} else if (!folio_test_hugetlb_freed(old_folio)) {
/*
@@ -3005,7 +3008,7 @@ int isolate_or_dissolve_huge_page(struct
if (hstate_is_gigantic(h))
return -ENOMEM;
- if (folio_ref_count(folio) && !isolate_hugetlb(folio, list))
+ if (folio_ref_count(folio) && isolate_hugetlb(folio, list))
ret = 0;
else if (!folio_ref_count(folio))
ret = alloc_and_dissolve_hugetlb_folio(h, folio, list);
@@ -7251,15 +7254,15 @@ __weak unsigned long hugetlb_mask_last_p
* These functions are overwritable if your architecture needs its own
* behavior.
*/
-int isolate_hugetlb(struct folio *folio, struct list_head *list)
+bool isolate_hugetlb(struct folio *folio, struct list_head *list)
{
- int ret = 0;
+ bool ret = true;
spin_lock_irq(&hugetlb_lock);
if (!folio_test_hugetlb(folio) ||
!folio_test_hugetlb_migratable(folio) ||
!folio_try_get(folio)) {
- ret = -EBUSY;
+ ret = false;
goto unlock;
}
folio_clear_hugetlb_migratable(folio);
--- a/mm/memory-failure.c~mm-hugetlb-change-to-return-bool-for-isolate_hugetlb
+++ a/mm/memory-failure.c
@@ -2508,7 +2508,7 @@ static bool isolate_page(struct page *pa
bool isolated = false;
if (PageHuge(page)) {
- isolated = !isolate_hugetlb(page_folio(page), pagelist);
+ isolated = isolate_hugetlb(page_folio(page), pagelist);
} else {
bool lru = !__PageMovable(page);
--- a/mm/mempolicy.c~mm-hugetlb-change-to-return-bool-for-isolate_hugetlb
+++ a/mm/mempolicy.c
@@ -609,7 +609,7 @@ static int queue_folios_hugetlb(pte_t *p
if (flags & (MPOL_MF_MOVE_ALL) ||
(flags & MPOL_MF_MOVE && folio_estimated_sharers(folio) == 1 &&
!hugetlb_pmd_shared(pte))) {
- if (isolate_hugetlb(folio, qp->pagelist) &&
+ if (!isolate_hugetlb(folio, qp->pagelist) &&
(flags & MPOL_MF_STRICT))
/*
* Failed to isolate folio but allow migrating pages
--- a/mm/migrate.c~mm-hugetlb-change-to-return-bool-for-isolate_hugetlb
+++ a/mm/migrate.c
@@ -2095,6 +2095,7 @@ static int add_page_for_migration(struct
struct vm_area_struct *vma;
struct page *page;
int err;
+ bool isolated;
mmap_read_lock(mm);
err = -EFAULT;
@@ -2126,13 +2127,11 @@ static int add_page_for_migration(struct
if (PageHuge(page)) {
if (PageHead(page)) {
- err = isolate_hugetlb(page_folio(page), pagelist);
- if (!err)
- err = 1;
+ isolated = isolate_hugetlb(page_folio(page), pagelist);
+ err = isolated ? 1 : -EBUSY;
}
} else {
struct page *head;
- bool isolated;
head = compound_head(page);
isolated = isolate_lru_page(head);
_
Patches currently in -mm which might be from baolin.wang@xxxxxxxxxxxxxxxxx are
mm-change-to-return-bool-for-folio_isolate_lru.patch
mm-change-to-return-bool-for-isolate_lru_page.patch
mm-hugetlb-change-to-return-bool-for-isolate_hugetlb.patch
mm-change-to-return-bool-for-isolate_movable_page.patch
