The patch titled
Subject: hugetlb: remove mention of destructors
has been added to the -mm mm-unstable branch. Its filename is
hugetlb-remove-mention-of-destructors.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hugetlb-remove-mention-of-destructors.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: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: hugetlb: remove mention of destructors
Date: Thu, 21 Mar 2024 14:24:47 +0000
We no longer have destructors or dtors, merely a page flag (technically a
page type flag, but that's an implementation detail). Remove
__clear_hugetlb_destructor, fix up comments and the occasional variable
name.
Link: https://lkml.kernel.org/r/20240321142448.1645400-10-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 42 +++++++++++++++++-------------------------
1 file changed, 17 insertions(+), 25 deletions(-)
--- a/mm/hugetlb.c~hugetlb-remove-mention-of-destructors
+++ a/mm/hugetlb.c
@@ -1619,19 +1619,11 @@ static inline void destroy_compound_giga
unsigned int order) { }
#endif
-static inline void __clear_hugetlb_destructor(struct hstate *h,
- struct folio *folio)
-{
- lockdep_assert_held(&hugetlb_lock);
-
- __folio_clear_hugetlb(folio);
-}
-
/*
* Remove hugetlb folio from lists.
- * If vmemmap exists for the folio, update dtor so that the folio appears
- * as just a compound page. Otherwise, wait until after allocating vmemmap
- * to update dtor.
+ * If vmemmap exists for the folio, clear the hugetlb flag so that the
+ * folio appears as just a compound page. Otherwise, wait until after
+ * allocating vmemmap to clear the flag.
*
* A reference is held on the folio, except in the case of demote.
*
@@ -1662,12 +1654,12 @@ static void __remove_hugetlb_folio(struc
}
/*
- * We can only clear the hugetlb destructor after allocating vmemmap
+ * We can only clear the hugetlb flag after allocating vmemmap
* pages. Otherwise, someone (memory error handling) may try to write
* to tail struct pages.
*/
if (!folio_test_hugetlb_vmemmap_optimized(folio))
- __clear_hugetlb_destructor(h, folio);
+ __folio_clear_hugetlb(folio);
/*
* In the case of demote we do not ref count the page as it will soon
@@ -1741,7 +1733,7 @@ static void add_hugetlb_folio(struct hst
static void __update_and_free_hugetlb_folio(struct hstate *h,
struct folio *folio)
{
- bool clear_dtor = folio_test_hugetlb_vmemmap_optimized(folio);
+ bool clear_flag = folio_test_hugetlb_vmemmap_optimized(folio);
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
return;
@@ -1754,11 +1746,11 @@ static void __update_and_free_hugetlb_fo
return;
/*
- * If folio is not vmemmap optimized (!clear_dtor), then the folio
+ * If folio is not vmemmap optimized (!clear_flag), then the folio
* is no longer identified as a hugetlb page. hugetlb_vmemmap_restore_folio
* can only be passed hugetlb pages and will BUG otherwise.
*/
- if (clear_dtor && hugetlb_vmemmap_restore_folio(h, folio)) {
+ if (clear_flag && hugetlb_vmemmap_restore_folio(h, folio)) {
spin_lock_irq(&hugetlb_lock);
/*
* If we cannot allocate vmemmap pages, just refuse to free the
@@ -1779,11 +1771,11 @@ static void __update_and_free_hugetlb_fo
/*
* If vmemmap pages were allocated above, then we need to clear the
- * hugetlb destructor under the hugetlb lock.
+ * hugetlb flag under the hugetlb lock.
*/
- if (clear_dtor) {
+ if (clear_flag) {
spin_lock_irq(&hugetlb_lock);
- __clear_hugetlb_destructor(h, folio);
+ __folio_clear_hugetlb(folio);
spin_unlock_irq(&hugetlb_lock);
}
@@ -1885,7 +1877,7 @@ static void bulk_vmemmap_restore_error(s
list_for_each_entry_safe(folio, t_folio, non_hvo_folios, lru) {
list_del(&folio->lru);
spin_lock_irq(&hugetlb_lock);
- __clear_hugetlb_destructor(h, folio);
+ __folio_clear_hugetlb(folio);
spin_unlock_irq(&hugetlb_lock);
update_and_free_hugetlb_folio(h, folio, false);
cond_resched();
@@ -1910,7 +1902,7 @@ static void bulk_vmemmap_restore_error(s
} else {
list_del(&folio->lru);
spin_lock_irq(&hugetlb_lock);
- __clear_hugetlb_destructor(h, folio);
+ __folio_clear_hugetlb(folio);
spin_unlock_irq(&hugetlb_lock);
update_and_free_hugetlb_folio(h, folio, false);
cond_resched();
@@ -1943,14 +1935,14 @@ retry:
* should only be pages on the non_hvo_folios list.
* Do note that the non_hvo_folios list could be empty.
* Without HVO enabled, ret will be 0 and there is no need to call
- * __clear_hugetlb_destructor as this was done previously.
+ * __folio_clear_hugetlb as this was done previously.
*/
VM_WARN_ON(!list_empty(folio_list));
VM_WARN_ON(ret < 0);
if (!list_empty(&non_hvo_folios) && ret) {
spin_lock_irq(&hugetlb_lock);
list_for_each_entry(folio, &non_hvo_folios, lru)
- __clear_hugetlb_destructor(h, folio);
+ __folio_clear_hugetlb(folio);
spin_unlock_irq(&hugetlb_lock);
}
@@ -1975,7 +1967,7 @@ void free_huge_folio(struct folio *folio
{
/*
* Can't pass hstate in here because it is called from the
- * compound page destructor.
+ * generic mm code.
*/
struct hstate *h = folio_hstate(folio);
int nid = folio_nid(folio);
@@ -2125,7 +2117,7 @@ static bool __prep_compound_gigantic_fol
set_compound_head(p, &folio->page);
}
__folio_set_head(folio);
- /* we rely on prep_new_hugetlb_folio to set the destructor */
+ /* we rely on prep_new_hugetlb_folio to set the hugetlb flag */
folio_set_order(folio, order);
atomic_set(&folio->_entire_mapcount, -1);
atomic_set(&folio->_nr_pages_mapped, 0);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-increase-folio-batch-size.patch
mm-always-initialise-folio-_deferred_list.patch
mm-create-folio_flag_false-and-folio_type_ops-macros.patch
mm-remove-folio_prep_large_rmappable.patch
mm-support-page_mapcount-on-page_has_type-pages.patch
mm-turn-folio_test_hugetlb-into-a-pagetype.patch
mm-remove-a-call-to-compound_head-from-is_page_hwpoison.patch
mm-free-up-pg_slab.patch
mm-improve-dumping-of-mapcount-and-page_type.patch
hugetlb-remove-mention-of-destructors.patch
