* + mm-huge_memory-remove-the-old-unused-__split_huge_page.patch added to mm-unstable branch
@ 2025-02-26 21:14 Andrew Morton
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Morton @ 2025-02-26 21:14 UTC (permalink / raw)
To: mm-commits, yuzhao, yang, willy, wangkefeng.wang, ryan.roberts,
linmiaohe, kirill.shutemov, kasong, jhubbard, hughd, david,
baolin.wang, ziy, akpm
The patch titled
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-remove-the-old-unused-__split_huge_page.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: Zi Yan <ziy@nvidia.com>
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
Date: Wed, 26 Feb 2025 16:00:28 -0500
Now split_huge_page_to_list_to_order() uses the new backend split code in
__folio_split_without_mapping(), the old __split_huge_page() and
__split_huge_page_tail() can be removed.
Link: https://lkml.kernel.org/r/20250226210032.2044041-6-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Kairui Song <kasong@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 207 ---------------------------------------------
1 file changed, 207 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-remove-the-old-unused-__split_huge_page
+++ a/mm/huge_memory.c
@@ -3286,213 +3286,6 @@ static void lru_add_page_tail(struct fol
}
}
-static void __split_huge_page_tail(struct folio *folio, int tail,
- struct lruvec *lruvec, struct list_head *list,
- unsigned int new_order)
-{
- struct page *head = &folio->page;
- struct page *page_tail = head + tail;
- /*
- * Careful: new_folio is not a "real" folio before we cleared PageTail.
- * Don't pass it around before clear_compound_head().
- */
- struct folio *new_folio = (struct folio *)page_tail;
-
- VM_BUG_ON_PAGE(atomic_read(&page_tail->_mapcount) != -1, page_tail);
-
- /*
- * Clone page flags before unfreezing refcount.
- *
- * After successful get_page_unless_zero() might follow flags change,
- * for example lock_page() which set PG_waiters.
- *
- * Note that for mapped sub-pages of an anonymous THP,
- * PG_anon_exclusive has been cleared in unmap_folio() and is stored in
- * the migration entry instead from where remap_page() will restore it.
- * We can still have PG_anon_exclusive set on effectively unmapped and
- * unreferenced sub-pages of an anonymous THP: we can simply drop
- * PG_anon_exclusive (-> PG_mappedtodisk) for these here.
- */
- page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
- page_tail->flags |= (head->flags &
- ((1L << PG_referenced) |
- (1L << PG_swapbacked) |
- (1L << PG_swapcache) |
- (1L << PG_mlocked) |
- (1L << PG_uptodate) |
- (1L << PG_active) |
- (1L << PG_workingset) |
- (1L << PG_locked) |
- (1L << PG_unevictable) |
-#ifdef CONFIG_ARCH_USES_PG_ARCH_2
- (1L << PG_arch_2) |
-#endif
-#ifdef CONFIG_ARCH_USES_PG_ARCH_3
- (1L << PG_arch_3) |
-#endif
- (1L << PG_dirty) |
- LRU_GEN_MASK | LRU_REFS_MASK));
-
- /* ->mapping in first and second tail page is replaced by other uses */
- VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING,
- page_tail);
- new_folio->mapping = folio->mapping;
- new_folio->index = folio->index + tail;
-
- /*
- * page->private should not be set in tail pages. Fix up and warn once
- * if private is unexpectedly set.
- */
- if (unlikely(page_tail->private)) {
- VM_WARN_ON_ONCE_PAGE(true, page_tail);
- page_tail->private = 0;
- }
- if (folio_test_swapcache(folio))
- new_folio->swap.val = folio->swap.val + tail;
-
- /* Page flags must be visible before we make the page non-compound. */
- smp_wmb();
-
- /*
- * Clear PageTail before unfreezing page refcount.
- *
- * After successful get_page_unless_zero() might follow put_page()
- * which needs correct compound_head().
- */
- clear_compound_head(page_tail);
- if (new_order) {
- prep_compound_page(page_tail, new_order);
- folio_set_large_rmappable(new_folio);
- }
-
- /* Finally unfreeze refcount. Additional reference from page cache. */
- page_ref_unfreeze(page_tail,
- 1 + ((!folio_test_anon(folio) || folio_test_swapcache(folio)) ?
- folio_nr_pages(new_folio) : 0));
-
- if (folio_test_young(folio))
- folio_set_young(new_folio);
- if (folio_test_idle(folio))
- folio_set_idle(new_folio);
-
- folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio));
-
- /*
- * always add to the tail because some iterators expect new
- * pages to show after the currently processed elements - e.g.
- * migrate_pages
- */
- lru_add_page_tail(folio, page_tail, lruvec, list);
-}
-
-static void __split_huge_page(struct page *page, struct list_head *list,
- pgoff_t end, unsigned int new_order)
-{
- struct folio *folio = page_folio(page);
- struct page *head = &folio->page;
- struct lruvec *lruvec;
- struct address_space *swap_cache = NULL;
- unsigned long offset = 0;
- int i, nr_dropped = 0;
- unsigned int new_nr = 1 << new_order;
- int order = folio_order(folio);
- unsigned int nr = 1 << order;
-
- /* complete memcg works before add pages to LRU */
- split_page_memcg(head, order, new_order);
-
- if (folio_test_anon(folio) && folio_test_swapcache(folio)) {
- offset = swap_cache_index(folio->swap);
- swap_cache = swap_address_space(folio->swap);
- xa_lock(&swap_cache->i_pages);
- }
-
- /* lock lru list/PageCompound, ref frozen by page_ref_freeze */
- lruvec = folio_lruvec_lock(folio);
-
- folio_clear_has_hwpoisoned(folio);
-
- for (i = nr - new_nr; i >= new_nr; i -= new_nr) {
- struct folio *tail;
- __split_huge_page_tail(folio, i, lruvec, list, new_order);
- tail = page_folio(head + i);
- /* Some pages can be beyond EOF: drop them from page cache */
- if (tail->index >= end) {
- if (shmem_mapping(folio->mapping))
- nr_dropped += new_nr;
- else if (folio_test_clear_dirty(tail))
- folio_account_cleaned(tail,
- inode_to_wb(folio->mapping->host));
- __filemap_remove_folio(tail, NULL);
- folio_put(tail);
- } else if (!folio_test_anon(folio)) {
- __xa_store(&folio->mapping->i_pages, tail->index,
- tail, 0);
- } else if (swap_cache) {
- __xa_store(&swap_cache->i_pages, offset + i,
- tail, 0);
- }
- }
-
- if (!new_order)
- ClearPageCompound(head);
- else {
- struct folio *new_folio = (struct folio *)head;
-
- folio_set_order(new_folio, new_order);
- }
- unlock_page_lruvec(lruvec);
- /* Caller disabled irqs, so they are still disabled here */
-
- split_page_owner(head, order, new_order);
- pgalloc_tag_split(folio, order, new_order);
-
- /* See comment in __split_huge_page_tail() */
- if (folio_test_anon(folio)) {
- /* Additional pin to swap cache */
- if (folio_test_swapcache(folio)) {
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&swap_cache->i_pages);
- } else {
- folio_ref_inc(folio);
- }
- } else {
- /* Additional pin to page cache */
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&folio->mapping->i_pages);
- }
- local_irq_enable();
-
- if (nr_dropped)
- shmem_uncharge(folio->mapping->host, nr_dropped);
- remap_page(folio, nr, PageAnon(head) ? RMP_USE_SHARED_ZEROPAGE : 0);
-
- /*
- * set page to its compound_head when split to non order-0 pages, so
- * we can skip unlocking it below, since PG_locked is transferred to
- * the compound_head of the page and the caller will unlock it.
- */
- if (new_order)
- page = compound_head(page);
-
- for (i = 0; i < nr; i += new_nr) {
- struct page *subpage = head + i;
- struct folio *new_folio = page_folio(subpage);
- if (subpage == page)
- continue;
- folio_unlock(new_folio);
-
- /*
- * Subpages may be freed if there wasn't any mapping
- * like if add_to_swap() is running on a lru page that
- * had its mapping zapped. And freeing these pages
- * requires taking the lru_lock so we do the put_page
- * of the tail pages after the split is complete.
- */
- free_page_and_swap_cache(subpage);
- }
-}
-
/* Racy check whether the huge page can be split */
bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
{
_
Patches currently in -mm which might be from ziy@nvidia.com are
selftests-mm-make-file-backed-thp-split-work-by-writing-pmd-size-data.patch
mm-huge_memory-allow-split-shmem-large-folio-to-any-lower-order.patch
selftests-mm-test-splitting-file-backed-thp-to-any-lower-order.patch
xarray-add-xas_try_split-to-split-a-multi-index-entry.patch
mm-huge_memory-add-two-new-not-yet-used-functions-for-folio_split.patch
mm-huge_memory-move-folio-split-common-code-to-__folio_split.patch
mm-huge_memory-add-buddy-allocator-like-non-uniform-folio_split.patch
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
mm-huge_memory-add-folio_split-to-debugfs-testing-interface.patch
mm-truncate-use-buddy-allocator-like-folio-split-for-truncate-operation.patch
selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split.patch
mm-filemap-use-xas_try_split-in-__filemap_add_folio.patch
mm-shmem-use-xas_try_split-in-shmem_split_large_entry.patch
mm-shmem-use-xas_try_split-in-shmem_split_large_entry-fix.patch
^ permalink raw reply [flat|nested] 5+ messages in thread* + mm-huge_memory-remove-the-old-unused-__split_huge_page.patch added to mm-unstable branch
@ 2025-03-07 20:27 Andrew Morton
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Morton @ 2025-03-07 20:27 UTC (permalink / raw)
To: mm-commits, yuzhao, yang, willy, wangkefeng.wang, ryan.roberts,
linmiaohe, kirill.shutemov, kasong, jhubbard, hughd, david,
baolin.wang, ziy, akpm
The patch titled
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-remove-the-old-unused-__split_huge_page.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: Zi Yan <ziy@nvidia.com>
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
Date: Fri, 7 Mar 2025 12:39:58 -0500
Now split_huge_page_to_list_to_order() uses the new backend split code in
__split_unmapped_folio(), the old __split_huge_page() and
__split_huge_page_tail() can be removed.
Link: https://lkml.kernel.org/r/20250307174001.242794-6-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Kairui Song <kasong@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 215 ---------------------------------------------
1 file changed, 215 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-remove-the-old-unused-__split_huge_page
+++ a/mm/huge_memory.c
@@ -3284,221 +3284,6 @@ static void lru_add_page_tail(struct fol
}
}
-static void __split_huge_page_tail(struct folio *folio, int tail,
- struct lruvec *lruvec, struct list_head *list,
- unsigned int new_order)
-{
- struct page *head = &folio->page;
- struct page *page_tail = head + tail;
- /*
- * Careful: new_folio is not a "real" folio before we cleared PageTail.
- * Don't pass it around before clear_compound_head().
- */
- struct folio *new_folio = (struct folio *)page_tail;
-
- VM_BUG_ON_PAGE(atomic_read(&page_tail->_mapcount) != -1, page_tail);
-
- /*
- * Clone page flags before unfreezing refcount.
- *
- * After successful get_page_unless_zero() might follow flags change,
- * for example lock_page() which set PG_waiters.
- *
- * Note that for mapped sub-pages of an anonymous THP,
- * PG_anon_exclusive has been cleared in unmap_folio() and is stored in
- * the migration entry instead from where remap_page() will restore it.
- * We can still have PG_anon_exclusive set on effectively unmapped and
- * unreferenced sub-pages of an anonymous THP: we can simply drop
- * PG_anon_exclusive (-> PG_mappedtodisk) for these here.
- */
- page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
- page_tail->flags |= (head->flags &
- ((1L << PG_referenced) |
- (1L << PG_swapbacked) |
- (1L << PG_swapcache) |
- (1L << PG_mlocked) |
- (1L << PG_uptodate) |
- (1L << PG_active) |
- (1L << PG_workingset) |
- (1L << PG_locked) |
- (1L << PG_unevictable) |
-#ifdef CONFIG_ARCH_USES_PG_ARCH_2
- (1L << PG_arch_2) |
-#endif
-#ifdef CONFIG_ARCH_USES_PG_ARCH_3
- (1L << PG_arch_3) |
-#endif
- (1L << PG_dirty) |
- LRU_GEN_MASK | LRU_REFS_MASK));
-
- /* ->mapping in first and second tail page is replaced by other uses */
- VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING,
- page_tail);
- new_folio->mapping = folio->mapping;
- new_folio->index = folio->index + tail;
-
- /*
- * page->private should not be set in tail pages. Fix up and warn once
- * if private is unexpectedly set.
- */
- if (unlikely(page_tail->private)) {
- VM_WARN_ON_ONCE_PAGE(true, page_tail);
- page_tail->private = 0;
- }
- if (folio_test_swapcache(folio))
- new_folio->swap.val = folio->swap.val + tail;
-
- /* Page flags must be visible before we make the page non-compound. */
- smp_wmb();
-
- /*
- * Clear PageTail before unfreezing page refcount.
- *
- * After successful get_page_unless_zero() might follow put_page()
- * which needs correct compound_head().
- */
- clear_compound_head(page_tail);
- if (new_order) {
- prep_compound_page(page_tail, new_order);
- folio_set_large_rmappable(new_folio);
- }
-
- /* Finally unfreeze refcount. Additional reference from page cache. */
- page_ref_unfreeze(page_tail,
- 1 + ((!folio_test_anon(folio) || folio_test_swapcache(folio)) ?
- folio_nr_pages(new_folio) : 0));
-
- if (folio_test_young(folio))
- folio_set_young(new_folio);
- if (folio_test_idle(folio))
- folio_set_idle(new_folio);
-
- folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio));
-
- /*
- * always add to the tail because some iterators expect new
- * pages to show after the currently processed elements - e.g.
- * migrate_pages
- */
- lru_add_page_tail(folio, page_tail, lruvec, list);
-}
-
-static void __split_huge_page(struct page *page, struct list_head *list,
- pgoff_t end, unsigned int new_order)
-{
- struct folio *folio = page_folio(page);
- struct page *head = &folio->page;
- struct lruvec *lruvec;
- struct address_space *swap_cache = NULL;
- unsigned long offset = 0;
- int i, nr_dropped = 0;
- unsigned int new_nr = 1 << new_order;
- int order = folio_order(folio);
- unsigned int nr = 1 << order;
-
- /*
- * Reset any memcg data overlay in the tail pages. folio_nr_pages()
- * is unreliable after this point.
- */
-#ifdef NR_PAGES_IN_LARGE_FOLIO
- folio->_nr_pages = 0;
-#endif
-
- /* complete memcg works before add pages to LRU */
- split_page_memcg(head, order, new_order);
-
- if (folio_test_anon(folio) && folio_test_swapcache(folio)) {
- offset = swap_cache_index(folio->swap);
- swap_cache = swap_address_space(folio->swap);
- xa_lock(&swap_cache->i_pages);
- }
-
- /* lock lru list/PageCompound, ref frozen by page_ref_freeze */
- lruvec = folio_lruvec_lock(folio);
-
- folio_clear_has_hwpoisoned(folio);
-
- for (i = nr - new_nr; i >= new_nr; i -= new_nr) {
- struct folio *tail;
- __split_huge_page_tail(folio, i, lruvec, list, new_order);
- tail = page_folio(head + i);
- /* Some pages can be beyond EOF: drop them from page cache */
- if (tail->index >= end) {
- if (shmem_mapping(folio->mapping))
- nr_dropped += new_nr;
- else if (folio_test_clear_dirty(tail))
- folio_account_cleaned(tail,
- inode_to_wb(folio->mapping->host));
- __filemap_remove_folio(tail, NULL);
- folio_put(tail);
- } else if (!folio_test_anon(folio)) {
- __xa_store(&folio->mapping->i_pages, tail->index,
- tail, 0);
- } else if (swap_cache) {
- __xa_store(&swap_cache->i_pages, offset + i,
- tail, 0);
- }
- }
-
- if (!new_order)
- ClearPageCompound(head);
- else {
- struct folio *new_folio = (struct folio *)head;
-
- folio_set_order(new_folio, new_order);
- }
- unlock_page_lruvec(lruvec);
- /* Caller disabled irqs, so they are still disabled here */
-
- split_page_owner(head, order, new_order);
- pgalloc_tag_split(folio, order, new_order);
-
- /* See comment in __split_huge_page_tail() */
- if (folio_test_anon(folio)) {
- /* Additional pin to swap cache */
- if (folio_test_swapcache(folio)) {
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&swap_cache->i_pages);
- } else {
- folio_ref_inc(folio);
- }
- } else {
- /* Additional pin to page cache */
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&folio->mapping->i_pages);
- }
- local_irq_enable();
-
- if (nr_dropped)
- shmem_uncharge(folio->mapping->host, nr_dropped);
- remap_page(folio, nr, PageAnon(head) ? RMP_USE_SHARED_ZEROPAGE : 0);
-
- /*
- * set page to its compound_head when split to non order-0 pages, so
- * we can skip unlocking it below, since PG_locked is transferred to
- * the compound_head of the page and the caller will unlock it.
- */
- if (new_order)
- page = compound_head(page);
-
- for (i = 0; i < nr; i += new_nr) {
- struct page *subpage = head + i;
- struct folio *new_folio = page_folio(subpage);
- if (subpage == page)
- continue;
- folio_unlock(new_folio);
-
- /*
- * Subpages may be freed if there wasn't any mapping
- * like if add_to_swap() is running on a lru page that
- * had its mapping zapped. And freeing these pages
- * requires taking the lru_lock so we do the put_page
- * of the tail pages after the split is complete.
- */
- free_page_and_swap_cache(subpage);
- }
-}
-
/* Racy check whether the huge page can be split */
bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
{
_
Patches currently in -mm which might be from ziy@nvidia.com are
mm-migrate-fix-shmem-xarray-update-during-migration.patch
selftests-mm-make-file-backed-thp-split-work-by-writing-pmd-size-data.patch
mm-huge_memory-allow-split-shmem-large-folio-to-any-lower-order.patch
selftests-mm-test-splitting-file-backed-thp-to-any-lower-order.patch
xarray-add-xas_try_split-to-split-a-multi-index-entry.patch
mm-huge_memory-add-two-new-not-yet-used-functions-for-folio_split.patch
mm-huge_memory-move-folio-split-common-code-to-__folio_split.patch
mm-huge_memory-add-buddy-allocator-like-non-uniform-folio_split.patch
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
mm-huge_memory-add-folio_split-to-debugfs-testing-interface.patch
mm-truncate-use-folio_split-in-truncate-operation.patch
selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split.patch
^ permalink raw reply [flat|nested] 5+ messages in thread* + mm-huge_memory-remove-the-old-unused-__split_huge_page.patch added to mm-unstable branch
@ 2025-02-19 1:10 Andrew Morton
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Morton @ 2025-02-19 1:10 UTC (permalink / raw)
To: mm-commits, yuzhao, yang, willy, wangkefeng.wang, ryan.roberts,
linmiaohe, kirill.shutemov, kasong, jhubbard, hughd, david,
baolin.wang, ziy, akpm
The patch titled
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-remove-the-old-unused-__split_huge_page.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: Zi Yan <ziy@nvidia.com>
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
Date: Tue, 18 Feb 2025 18:50:09 -0500
Now split_huge_page_to_list_to_order() uses the new backend split code in
__folio_split_without_mapping(), the old __split_huge_page() and
__split_huge_page_tail() can be removed.
Link: https://lkml.kernel.org/r/20250218235012.1542225-6-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Kairui Song <kasong@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 207 ---------------------------------------------
1 file changed, 207 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-remove-the-old-unused-__split_huge_page
+++ a/mm/huge_memory.c
@@ -3286,213 +3286,6 @@ static void lru_add_page_tail(struct fol
}
}
-static void __split_huge_page_tail(struct folio *folio, int tail,
- struct lruvec *lruvec, struct list_head *list,
- unsigned int new_order)
-{
- struct page *head = &folio->page;
- struct page *page_tail = head + tail;
- /*
- * Careful: new_folio is not a "real" folio before we cleared PageTail.
- * Don't pass it around before clear_compound_head().
- */
- struct folio *new_folio = (struct folio *)page_tail;
-
- VM_BUG_ON_PAGE(atomic_read(&page_tail->_mapcount) != -1, page_tail);
-
- /*
- * Clone page flags before unfreezing refcount.
- *
- * After successful get_page_unless_zero() might follow flags change,
- * for example lock_page() which set PG_waiters.
- *
- * Note that for mapped sub-pages of an anonymous THP,
- * PG_anon_exclusive has been cleared in unmap_folio() and is stored in
- * the migration entry instead from where remap_page() will restore it.
- * We can still have PG_anon_exclusive set on effectively unmapped and
- * unreferenced sub-pages of an anonymous THP: we can simply drop
- * PG_anon_exclusive (-> PG_mappedtodisk) for these here.
- */
- page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
- page_tail->flags |= (head->flags &
- ((1L << PG_referenced) |
- (1L << PG_swapbacked) |
- (1L << PG_swapcache) |
- (1L << PG_mlocked) |
- (1L << PG_uptodate) |
- (1L << PG_active) |
- (1L << PG_workingset) |
- (1L << PG_locked) |
- (1L << PG_unevictable) |
-#ifdef CONFIG_ARCH_USES_PG_ARCH_2
- (1L << PG_arch_2) |
-#endif
-#ifdef CONFIG_ARCH_USES_PG_ARCH_3
- (1L << PG_arch_3) |
-#endif
- (1L << PG_dirty) |
- LRU_GEN_MASK | LRU_REFS_MASK));
-
- /* ->mapping in first and second tail page is replaced by other uses */
- VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING,
- page_tail);
- new_folio->mapping = folio->mapping;
- new_folio->index = folio->index + tail;
-
- /*
- * page->private should not be set in tail pages. Fix up and warn once
- * if private is unexpectedly set.
- */
- if (unlikely(page_tail->private)) {
- VM_WARN_ON_ONCE_PAGE(true, page_tail);
- page_tail->private = 0;
- }
- if (folio_test_swapcache(folio))
- new_folio->swap.val = folio->swap.val + tail;
-
- /* Page flags must be visible before we make the page non-compound. */
- smp_wmb();
-
- /*
- * Clear PageTail before unfreezing page refcount.
- *
- * After successful get_page_unless_zero() might follow put_page()
- * which needs correct compound_head().
- */
- clear_compound_head(page_tail);
- if (new_order) {
- prep_compound_page(page_tail, new_order);
- folio_set_large_rmappable(new_folio);
- }
-
- /* Finally unfreeze refcount. Additional reference from page cache. */
- page_ref_unfreeze(page_tail,
- 1 + ((!folio_test_anon(folio) || folio_test_swapcache(folio)) ?
- folio_nr_pages(new_folio) : 0));
-
- if (folio_test_young(folio))
- folio_set_young(new_folio);
- if (folio_test_idle(folio))
- folio_set_idle(new_folio);
-
- folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio));
-
- /*
- * always add to the tail because some iterators expect new
- * pages to show after the currently processed elements - e.g.
- * migrate_pages
- */
- lru_add_page_tail(folio, page_tail, lruvec, list);
-}
-
-static void __split_huge_page(struct page *page, struct list_head *list,
- pgoff_t end, unsigned int new_order)
-{
- struct folio *folio = page_folio(page);
- struct page *head = &folio->page;
- struct lruvec *lruvec;
- struct address_space *swap_cache = NULL;
- unsigned long offset = 0;
- int i, nr_dropped = 0;
- unsigned int new_nr = 1 << new_order;
- int order = folio_order(folio);
- unsigned int nr = 1 << order;
-
- /* complete memcg works before add pages to LRU */
- split_page_memcg(head, order, new_order);
-
- if (folio_test_anon(folio) && folio_test_swapcache(folio)) {
- offset = swap_cache_index(folio->swap);
- swap_cache = swap_address_space(folio->swap);
- xa_lock(&swap_cache->i_pages);
- }
-
- /* lock lru list/PageCompound, ref frozen by page_ref_freeze */
- lruvec = folio_lruvec_lock(folio);
-
- folio_clear_has_hwpoisoned(folio);
-
- for (i = nr - new_nr; i >= new_nr; i -= new_nr) {
- struct folio *tail;
- __split_huge_page_tail(folio, i, lruvec, list, new_order);
- tail = page_folio(head + i);
- /* Some pages can be beyond EOF: drop them from page cache */
- if (tail->index >= end) {
- if (shmem_mapping(folio->mapping))
- nr_dropped += new_nr;
- else if (folio_test_clear_dirty(tail))
- folio_account_cleaned(tail,
- inode_to_wb(folio->mapping->host));
- __filemap_remove_folio(tail, NULL);
- folio_put(tail);
- } else if (!folio_test_anon(folio)) {
- __xa_store(&folio->mapping->i_pages, tail->index,
- tail, 0);
- } else if (swap_cache) {
- __xa_store(&swap_cache->i_pages, offset + i,
- tail, 0);
- }
- }
-
- if (!new_order)
- ClearPageCompound(head);
- else {
- struct folio *new_folio = (struct folio *)head;
-
- folio_set_order(new_folio, new_order);
- }
- unlock_page_lruvec(lruvec);
- /* Caller disabled irqs, so they are still disabled here */
-
- split_page_owner(head, order, new_order);
- pgalloc_tag_split(folio, order, new_order);
-
- /* See comment in __split_huge_page_tail() */
- if (folio_test_anon(folio)) {
- /* Additional pin to swap cache */
- if (folio_test_swapcache(folio)) {
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&swap_cache->i_pages);
- } else {
- folio_ref_inc(folio);
- }
- } else {
- /* Additional pin to page cache */
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&folio->mapping->i_pages);
- }
- local_irq_enable();
-
- if (nr_dropped)
- shmem_uncharge(folio->mapping->host, nr_dropped);
- remap_page(folio, nr, PageAnon(head) ? RMP_USE_SHARED_ZEROPAGE : 0);
-
- /*
- * set page to its compound_head when split to non order-0 pages, so
- * we can skip unlocking it below, since PG_locked is transferred to
- * the compound_head of the page and the caller will unlock it.
- */
- if (new_order)
- page = compound_head(page);
-
- for (i = 0; i < nr; i += new_nr) {
- struct page *subpage = head + i;
- struct folio *new_folio = page_folio(subpage);
- if (subpage == page)
- continue;
- folio_unlock(new_folio);
-
- /*
- * Subpages may be freed if there wasn't any mapping
- * like if add_to_swap() is running on a lru page that
- * had its mapping zapped. And freeing these pages
- * requires taking the lru_lock so we do the put_page
- * of the tail pages after the split is complete.
- */
- free_page_and_swap_cache(subpage);
- }
-}
-
/* Racy check whether the huge page can be split */
bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
{
_
Patches currently in -mm which might be from ziy@nvidia.com are
selftests-mm-make-file-backed-thp-split-work-by-writing-pmd-size-data.patch
mm-huge_memory-allow-split-shmem-large-folio-to-any-lower-order.patch
selftests-mm-test-splitting-file-backed-thp-to-any-lower-order.patch
xarray-add-xas_try_split-to-split-a-multi-index-entry.patch
mm-huge_memory-add-two-new-not-yet-used-functions-for-folio_split.patch
mm-huge_memory-move-folio-split-common-code-to-__folio_split.patch
mm-huge_memory-add-buddy-allocator-like-non-uniform-folio_split.patch
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
mm-huge_memory-add-folio_split-to-debugfs-testing-interface.patch
mm-truncate-use-buddy-allocator-like-folio-split-for-truncate-operation.patch
selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split.patch
mm-filemap-use-xas_try_split-in-__filemap_add_folio.patch
mm-shmem-use-xas_try_split-in-shmem_split_large_entry.patch
^ permalink raw reply [flat|nested] 5+ messages in thread* + mm-huge_memory-remove-the-old-unused-__split_huge_page.patch added to mm-unstable branch
@ 2025-02-11 23:03 Andrew Morton
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Morton @ 2025-02-11 23:03 UTC (permalink / raw)
To: mm-commits, yuzhao, yang, willy, wangkefeng.wang, ryan.roberts,
linmiaohe, kirill.shutemov, jhubbard, hughd, david, baolin.wang,
ziy, akpm
The patch titled
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-remove-the-old-unused-__split_huge_page.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: Zi Yan <ziy@nvidia.com>
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
Date: Tue, 11 Feb 2025 10:50:30 -0500
Now split_huge_page_to_list_to_order() uses the new backend split code in
__folio_split_without_mapping(), the old __split_huge_page() and
__split_huge_page_tail() can be removed.
Link: https://lkml.kernel.org/r/20250211155034.268962-6-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 207 ---------------------------------------------
1 file changed, 207 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-remove-the-old-unused-__split_huge_page
+++ a/mm/huge_memory.c
@@ -3271,213 +3271,6 @@ static void lru_add_page_tail(struct fol
}
}
-static void __split_huge_page_tail(struct folio *folio, int tail,
- struct lruvec *lruvec, struct list_head *list,
- unsigned int new_order)
-{
- struct page *head = &folio->page;
- struct page *page_tail = head + tail;
- /*
- * Careful: new_folio is not a "real" folio before we cleared PageTail.
- * Don't pass it around before clear_compound_head().
- */
- struct folio *new_folio = (struct folio *)page_tail;
-
- VM_BUG_ON_PAGE(atomic_read(&page_tail->_mapcount) != -1, page_tail);
-
- /*
- * Clone page flags before unfreezing refcount.
- *
- * After successful get_page_unless_zero() might follow flags change,
- * for example lock_page() which set PG_waiters.
- *
- * Note that for mapped sub-pages of an anonymous THP,
- * PG_anon_exclusive has been cleared in unmap_folio() and is stored in
- * the migration entry instead from where remap_page() will restore it.
- * We can still have PG_anon_exclusive set on effectively unmapped and
- * unreferenced sub-pages of an anonymous THP: we can simply drop
- * PG_anon_exclusive (-> PG_mappedtodisk) for these here.
- */
- page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
- page_tail->flags |= (head->flags &
- ((1L << PG_referenced) |
- (1L << PG_swapbacked) |
- (1L << PG_swapcache) |
- (1L << PG_mlocked) |
- (1L << PG_uptodate) |
- (1L << PG_active) |
- (1L << PG_workingset) |
- (1L << PG_locked) |
- (1L << PG_unevictable) |
-#ifdef CONFIG_ARCH_USES_PG_ARCH_2
- (1L << PG_arch_2) |
-#endif
-#ifdef CONFIG_ARCH_USES_PG_ARCH_3
- (1L << PG_arch_3) |
-#endif
- (1L << PG_dirty) |
- LRU_GEN_MASK | LRU_REFS_MASK));
-
- /* ->mapping in first and second tail page is replaced by other uses */
- VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING,
- page_tail);
- new_folio->mapping = folio->mapping;
- new_folio->index = folio->index + tail;
-
- /*
- * page->private should not be set in tail pages. Fix up and warn once
- * if private is unexpectedly set.
- */
- if (unlikely(page_tail->private)) {
- VM_WARN_ON_ONCE_PAGE(true, page_tail);
- page_tail->private = 0;
- }
- if (folio_test_swapcache(folio))
- new_folio->swap.val = folio->swap.val + tail;
-
- /* Page flags must be visible before we make the page non-compound. */
- smp_wmb();
-
- /*
- * Clear PageTail before unfreezing page refcount.
- *
- * After successful get_page_unless_zero() might follow put_page()
- * which needs correct compound_head().
- */
- clear_compound_head(page_tail);
- if (new_order) {
- prep_compound_page(page_tail, new_order);
- folio_set_large_rmappable(new_folio);
- }
-
- /* Finally unfreeze refcount. Additional reference from page cache. */
- page_ref_unfreeze(page_tail,
- 1 + ((!folio_test_anon(folio) || folio_test_swapcache(folio)) ?
- folio_nr_pages(new_folio) : 0));
-
- if (folio_test_young(folio))
- folio_set_young(new_folio);
- if (folio_test_idle(folio))
- folio_set_idle(new_folio);
-
- folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio));
-
- /*
- * always add to the tail because some iterators expect new
- * pages to show after the currently processed elements - e.g.
- * migrate_pages
- */
- lru_add_page_tail(folio, page_tail, lruvec, list);
-}
-
-static void __split_huge_page(struct page *page, struct list_head *list,
- pgoff_t end, unsigned int new_order)
-{
- struct folio *folio = page_folio(page);
- struct page *head = &folio->page;
- struct lruvec *lruvec;
- struct address_space *swap_cache = NULL;
- unsigned long offset = 0;
- int i, nr_dropped = 0;
- unsigned int new_nr = 1 << new_order;
- int order = folio_order(folio);
- unsigned int nr = 1 << order;
-
- /* complete memcg works before add pages to LRU */
- split_page_memcg(head, order, new_order);
-
- if (folio_test_anon(folio) && folio_test_swapcache(folio)) {
- offset = swap_cache_index(folio->swap);
- swap_cache = swap_address_space(folio->swap);
- xa_lock(&swap_cache->i_pages);
- }
-
- /* lock lru list/PageCompound, ref frozen by page_ref_freeze */
- lruvec = folio_lruvec_lock(folio);
-
- folio_clear_has_hwpoisoned(folio);
-
- for (i = nr - new_nr; i >= new_nr; i -= new_nr) {
- struct folio *tail;
- __split_huge_page_tail(folio, i, lruvec, list, new_order);
- tail = page_folio(head + i);
- /* Some pages can be beyond EOF: drop them from page cache */
- if (tail->index >= end) {
- if (shmem_mapping(folio->mapping))
- nr_dropped += new_nr;
- else if (folio_test_clear_dirty(tail))
- folio_account_cleaned(tail,
- inode_to_wb(folio->mapping->host));
- __filemap_remove_folio(tail, NULL);
- folio_put(tail);
- } else if (!folio_test_anon(folio)) {
- __xa_store(&folio->mapping->i_pages, tail->index,
- tail, 0);
- } else if (swap_cache) {
- __xa_store(&swap_cache->i_pages, offset + i,
- tail, 0);
- }
- }
-
- if (!new_order)
- ClearPageCompound(head);
- else {
- struct folio *new_folio = (struct folio *)head;
-
- folio_set_order(new_folio, new_order);
- }
- unlock_page_lruvec(lruvec);
- /* Caller disabled irqs, so they are still disabled here */
-
- split_page_owner(head, order, new_order);
- pgalloc_tag_split(folio, order, new_order);
-
- /* See comment in __split_huge_page_tail() */
- if (folio_test_anon(folio)) {
- /* Additional pin to swap cache */
- if (folio_test_swapcache(folio)) {
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&swap_cache->i_pages);
- } else {
- folio_ref_inc(folio);
- }
- } else {
- /* Additional pin to page cache */
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&folio->mapping->i_pages);
- }
- local_irq_enable();
-
- if (nr_dropped)
- shmem_uncharge(folio->mapping->host, nr_dropped);
- remap_page(folio, nr, PageAnon(head) ? RMP_USE_SHARED_ZEROPAGE : 0);
-
- /*
- * set page to its compound_head when split to non order-0 pages, so
- * we can skip unlocking it below, since PG_locked is transferred to
- * the compound_head of the page and the caller will unlock it.
- */
- if (new_order)
- page = compound_head(page);
-
- for (i = 0; i < nr; i += new_nr) {
- struct page *subpage = head + i;
- struct folio *new_folio = page_folio(subpage);
- if (subpage == page)
- continue;
- folio_unlock(new_folio);
-
- /*
- * Subpages may be freed if there wasn't any mapping
- * like if add_to_swap() is running on a lru page that
- * had its mapping zapped. And freeing these pages
- * requires taking the lru_lock so we do the put_page
- * of the tail pages after the split is complete.
- */
- free_page_and_swap_cache(subpage);
- }
-}
-
/* Racy check whether the huge page can be split */
bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
{
_
Patches currently in -mm which might be from ziy@nvidia.com are
selftests-mm-make-file-backed-thp-split-work-by-writing-pmd-size-data.patch
mm-huge_memory-allow-split-shmem-large-folio-to-any-lower-order.patch
selftests-mm-test-splitting-file-backed-thp-to-any-lower-order.patch
xarray-add-xas_try_split-to-split-a-multi-index-entry.patch
mm-huge_memory-add-two-new-not-yet-used-functions-for-folio_split.patch
mm-huge_memory-move-folio-split-common-code-to-__folio_split.patch
mm-huge_memory-add-buddy-allocator-like-non-uniform-folio_split.patch
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
mm-huge_memory-add-folio_split-to-debugfs-testing-interface.patch
mm-truncate-use-buddy-allocator-like-folio-split-for-truncate-operation.patch
selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split.patch
^ permalink raw reply [flat|nested] 5+ messages in thread* + mm-huge_memory-remove-the-old-unused-__split_huge_page.patch added to mm-unstable branch
@ 2025-02-06 8:05 Andrew Morton
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Morton @ 2025-02-06 8:05 UTC (permalink / raw)
To: mm-commits, yuzhao, yang, willy, wangkefeng.wang, ryan.roberts,
linmiaohe, kirill.shutemov, jhubbard, hughd, david, baolin.wang,
ziy, akpm
The patch titled
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-remove-the-old-unused-__split_huge_page.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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The -mm tree is included into linux-next via the mm-everything
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------------------------------------------------------
From: Zi Yan <ziy@nvidia.com>
Subject: mm/huge_memory: remove the old, unused __split_huge_page()
Date: Tue, 4 Feb 2025 22:14:14 -0500
Now split_huge_page_to_list_to_order() uses the new backend split code in
__folio_split_without_mapping(), the old __split_huge_page() and
__split_huge_page_tail() can be removed.
Link: https://lkml.kernel.org/r/20250205031417.1771278-5-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: linmiaohe <linmiaohe@huawei.com>
Cc: Mattew Wilcox <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 207 ---------------------------------------------
1 file changed, 207 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-remove-the-old-unused-__split_huge_page
+++ a/mm/huge_memory.c
@@ -3281,213 +3281,6 @@ static void lru_add_page_tail(struct fol
}
}
-static void __split_huge_page_tail(struct folio *folio, int tail,
- struct lruvec *lruvec, struct list_head *list,
- unsigned int new_order)
-{
- struct page *head = &folio->page;
- struct page *page_tail = head + tail;
- /*
- * Careful: new_folio is not a "real" folio before we cleared PageTail.
- * Don't pass it around before clear_compound_head().
- */
- struct folio *new_folio = (struct folio *)page_tail;
-
- VM_BUG_ON_PAGE(atomic_read(&page_tail->_mapcount) != -1, page_tail);
-
- /*
- * Clone page flags before unfreezing refcount.
- *
- * After successful get_page_unless_zero() might follow flags change,
- * for example lock_page() which set PG_waiters.
- *
- * Note that for mapped sub-pages of an anonymous THP,
- * PG_anon_exclusive has been cleared in unmap_folio() and is stored in
- * the migration entry instead from where remap_page() will restore it.
- * We can still have PG_anon_exclusive set on effectively unmapped and
- * unreferenced sub-pages of an anonymous THP: we can simply drop
- * PG_anon_exclusive (-> PG_mappedtodisk) for these here.
- */
- page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
- page_tail->flags |= (head->flags &
- ((1L << PG_referenced) |
- (1L << PG_swapbacked) |
- (1L << PG_swapcache) |
- (1L << PG_mlocked) |
- (1L << PG_uptodate) |
- (1L << PG_active) |
- (1L << PG_workingset) |
- (1L << PG_locked) |
- (1L << PG_unevictable) |
-#ifdef CONFIG_ARCH_USES_PG_ARCH_2
- (1L << PG_arch_2) |
-#endif
-#ifdef CONFIG_ARCH_USES_PG_ARCH_3
- (1L << PG_arch_3) |
-#endif
- (1L << PG_dirty) |
- LRU_GEN_MASK | LRU_REFS_MASK));
-
- /* ->mapping in first and second tail page is replaced by other uses */
- VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING,
- page_tail);
- new_folio->mapping = folio->mapping;
- new_folio->index = folio->index + tail;
-
- /*
- * page->private should not be set in tail pages. Fix up and warn once
- * if private is unexpectedly set.
- */
- if (unlikely(page_tail->private)) {
- VM_WARN_ON_ONCE_PAGE(true, page_tail);
- page_tail->private = 0;
- }
- if (folio_test_swapcache(folio))
- new_folio->swap.val = folio->swap.val + tail;
-
- /* Page flags must be visible before we make the page non-compound. */
- smp_wmb();
-
- /*
- * Clear PageTail before unfreezing page refcount.
- *
- * After successful get_page_unless_zero() might follow put_page()
- * which needs correct compound_head().
- */
- clear_compound_head(page_tail);
- if (new_order) {
- prep_compound_page(page_tail, new_order);
- folio_set_large_rmappable(new_folio);
- }
-
- /* Finally unfreeze refcount. Additional reference from page cache. */
- page_ref_unfreeze(page_tail,
- 1 + ((!folio_test_anon(folio) || folio_test_swapcache(folio)) ?
- folio_nr_pages(new_folio) : 0));
-
- if (folio_test_young(folio))
- folio_set_young(new_folio);
- if (folio_test_idle(folio))
- folio_set_idle(new_folio);
-
- folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio));
-
- /*
- * always add to the tail because some iterators expect new
- * pages to show after the currently processed elements - e.g.
- * migrate_pages
- */
- lru_add_page_tail(folio, page_tail, lruvec, list);
-}
-
-static void __split_huge_page(struct page *page, struct list_head *list,
- pgoff_t end, unsigned int new_order)
-{
- struct folio *folio = page_folio(page);
- struct page *head = &folio->page;
- struct lruvec *lruvec;
- struct address_space *swap_cache = NULL;
- unsigned long offset = 0;
- int i, nr_dropped = 0;
- unsigned int new_nr = 1 << new_order;
- int order = folio_order(folio);
- unsigned int nr = 1 << order;
-
- /* complete memcg works before add pages to LRU */
- split_page_memcg(head, order, new_order);
-
- if (folio_test_anon(folio) && folio_test_swapcache(folio)) {
- offset = swap_cache_index(folio->swap);
- swap_cache = swap_address_space(folio->swap);
- xa_lock(&swap_cache->i_pages);
- }
-
- /* lock lru list/PageCompound, ref frozen by page_ref_freeze */
- lruvec = folio_lruvec_lock(folio);
-
- folio_clear_has_hwpoisoned(folio);
-
- for (i = nr - new_nr; i >= new_nr; i -= new_nr) {
- struct folio *tail;
- __split_huge_page_tail(folio, i, lruvec, list, new_order);
- tail = page_folio(head + i);
- /* Some pages can be beyond EOF: drop them from page cache */
- if (tail->index >= end) {
- if (shmem_mapping(folio->mapping))
- nr_dropped += new_nr;
- else if (folio_test_clear_dirty(tail))
- folio_account_cleaned(tail,
- inode_to_wb(folio->mapping->host));
- __filemap_remove_folio(tail, NULL);
- folio_put(tail);
- } else if (!folio_test_anon(folio)) {
- __xa_store(&folio->mapping->i_pages, tail->index,
- tail, 0);
- } else if (swap_cache) {
- __xa_store(&swap_cache->i_pages, offset + i,
- tail, 0);
- }
- }
-
- if (!new_order)
- ClearPageCompound(head);
- else {
- struct folio *new_folio = (struct folio *)head;
-
- folio_set_order(new_folio, new_order);
- }
- unlock_page_lruvec(lruvec);
- /* Caller disabled irqs, so they are still disabled here */
-
- split_page_owner(head, order, new_order);
- pgalloc_tag_split(folio, order, new_order);
-
- /* See comment in __split_huge_page_tail() */
- if (folio_test_anon(folio)) {
- /* Additional pin to swap cache */
- if (folio_test_swapcache(folio)) {
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&swap_cache->i_pages);
- } else {
- folio_ref_inc(folio);
- }
- } else {
- /* Additional pin to page cache */
- folio_ref_add(folio, 1 + new_nr);
- xa_unlock(&folio->mapping->i_pages);
- }
- local_irq_enable();
-
- if (nr_dropped)
- shmem_uncharge(folio->mapping->host, nr_dropped);
- remap_page(folio, nr, PageAnon(head) ? RMP_USE_SHARED_ZEROPAGE : 0);
-
- /*
- * set page to its compound_head when split to non order-0 pages, so
- * we can skip unlocking it below, since PG_locked is transferred to
- * the compound_head of the page and the caller will unlock it.
- */
- if (new_order)
- page = compound_head(page);
-
- for (i = 0; i < nr; i += new_nr) {
- struct page *subpage = head + i;
- struct folio *new_folio = page_folio(subpage);
- if (subpage == page)
- continue;
- folio_unlock(new_folio);
-
- /*
- * Subpages may be freed if there wasn't any mapping
- * like if add_to_swap() is running on a lru page that
- * had its mapping zapped. And freeing these pages
- * requires taking the lru_lock so we do the put_page
- * of the tail pages after the split is complete.
- */
- free_page_and_swap_cache(subpage);
- }
-}
-
/* Racy check whether the huge page can be split */
bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
{
_
Patches currently in -mm which might be from ziy@nvidia.com are
selftests-mm-make-file-backed-thp-split-work-by-writing-pmd-size-data.patch
mm-huge_memory-allow-split-shmem-large-folio-to-any-lower-order.patch
selftests-mm-test-splitting-file-backed-thp-to-any-lower-order.patch
mm-huge_memory-add-two-new-not-yet-used-functions-for-folio_split.patch
mm-huge_memory-move-folio-split-common-code-to-__folio_split.patch
mm-huge_memory-add-buddy-allocator-like-folio_split.patch
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
mm-huge_memory-add-folio_split-to-debugfs-testing-interface.patch
mm-truncate-use-buddy-allocator-like-folio-split-for-truncate-operation.patch
selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split.patch
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