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Message-ID: <bf8e0c95-15a1-4eac-ba2e-52d361050039@nvidia.com>
Date: Thu, 13 Nov 2025 10:49:55 +1100
From: Balbir Singh <balbirs@...dia.com>
To: "David Hildenbrand (Red Hat)" <david@...nel.org>, linux-mm@...ck.org
Cc: linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
Zi Yan <ziy@...dia.com>, Joshua Hahn <joshua.hahnjy@...il.com>,
Rakie Kim <rakie.kim@...com>, Byungchul Park <byungchul@...com>,
Gregory Price <gourry@...rry.net>, Ying Huang
<ying.huang@...ux.alibaba.com>, Alistair Popple <apopple@...dia.com>,
Oscar Salvador <osalvador@...e.de>,
Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
Baolin Wang <baolin.wang@...ux.alibaba.com>,
"Liam R. Howlett" <Liam.Howlett@...cle.com>, Nico Pache <npache@...hat.com>,
Ryan Roberts <ryan.roberts@....com>, Dev Jain <dev.jain@....com>,
Barry Song <baohua@...nel.org>, Lyude Paul <lyude@...hat.com>,
Danilo Krummrich <dakr@...nel.org>, David Airlie <airlied@...il.com>,
Simona Vetter <simona@...ll.ch>, Ralph Campbell <rcampbell@...dia.com>,
Mika Penttilä <mpenttil@...hat.com>,
Matthew Brost <matthew.brost@...el.com>,
Francois Dugast <francois.dugast@...el.com>
Subject: Re: [PATCH] mm/huge_memory.c: introduce split_unmapped_folio_to_order
On 11/12/25 22:34, David Hildenbrand (Red Hat) wrote:
> On 12.11.25 11:17, Balbir Singh wrote:
>> On 11/12/25 21:00, David Hildenbrand (Red Hat) wrote:
>>> On 12.11.25 05:46, Balbir Singh wrote:
>>>> Unmapped was added as a parameter to __folio_split() and related
>>>> call sites to support splitting of folios already in the midst
>>>> of a migration. This special case arose for device private folio
>>>> migration since during migration there could be a disconnect between
>>>> source and destination on the folio size.
>>>>
>>>> Introduce split_unmapped_folio_to_order() to handle this special case.
>>>> This in turn removes the special casing introduced by the unmapped
>>>> parameter in __folio_split().
>>>
>>> As raised recently, I would hope that we can find a way to make all these splitting functions look more similar in the long term, ideally starting with "folio_split" / "folio_try_split".
>>>
>>> What about
>>>
>>> folio_split_unmapped()
>>>
>>> Do we really have to spell out the "to order" part in the function name?
>>>
>>> And if it's more a mostly-internal helper, maybe
>>>
>>> __folio_split_unmapped()
>>>
>>> subject: "mm/huge_memory: introduce ..."
>>>
>>
>> I can rename it, but currently it confirms to the split_folio with order in the name
>> The order is there in the name because in the future with mTHP we will want to
>> support splitting to various orders.
>
> I think we should start naming them more consistently regarding folio_split() immediately and cleanup the other ones later.
>
> I don't understand why "_to_order" must be in the name right now. You can add another variant and start using longer names when really required.
>
Ack
>>
>>
>>>>
>>>> Cc: Andrew Morton <akpm@...ux-foundation.org>
>>>> Cc: David Hildenbrand <david@...hat.com>
>>>> Cc: Zi Yan <ziy@...dia.com>
>>>> Cc: Joshua Hahn <joshua.hahnjy@...il.com>
>>>> Cc: Rakie Kim <rakie.kim@...com>
>>>> Cc: Byungchul Park <byungchul@...com>
>>>> Cc: Gregory Price <gourry@...rry.net>
>>>> Cc: Ying Huang <ying.huang@...ux.alibaba.com>
>>>> Cc: Alistair Popple <apopple@...dia.com>
>>>> Cc: Oscar Salvador <osalvador@...e.de>
>>>> Cc: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
>>>> Cc: Baolin Wang <baolin.wang@...ux.alibaba.com>
>>>> Cc: "Liam R. Howlett" <Liam.Howlett@...cle.com>
>>>> Cc: Nico Pache <npache@...hat.com>
>>>> Cc: Ryan Roberts <ryan.roberts@....com>
>>>> Cc: Dev Jain <dev.jain@....com>
>>>> Cc: Barry Song <baohua@...nel.org>
>>>> Cc: Lyude Paul <lyude@...hat.com>
>>>> Cc: Danilo Krummrich <dakr@...nel.org>
>>>> Cc: David Airlie <airlied@...il.com>
>>>> Cc: Simona Vetter <simona@...ll.ch>
>>>> Cc: Ralph Campbell <rcampbell@...dia.com>
>>>> Cc: Mika Penttilä <mpenttil@...hat.com>
>>>> Cc: Matthew Brost <matthew.brost@...el.com>
>>>> Cc: Francois Dugast <francois.dugast@...el.com>
>>>>
>>>> Suggested-by: Zi Yan <ziy@...dia.com>
>>>> Signed-off-by: Balbir Singh <balbirs@...dia.com>
>>>> ---
>>>> include/linux/huge_mm.h | 5 +-
>>>> mm/huge_memory.c | 135 ++++++++++++++++++++++++++++++++++------
>>>> mm/migrate_device.c | 3 +-
>>>> 3 files changed, 120 insertions(+), 23 deletions(-)
>>>>
>>>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>>>> index e2e91aa1a042..9155e683c08a 100644
>>>> --- a/include/linux/huge_mm.h
>>>> +++ b/include/linux/huge_mm.h
>>>> @@ -371,7 +371,8 @@ enum split_type {
>>>> bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins);
>>>> int __split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
>>>> - unsigned int new_order, bool unmapped);
>>>> + unsigned int new_order);
>>>> +int split_unmapped_folio_to_order(struct folio *folio, unsigned int new_order);
>>>> int min_order_for_split(struct folio *folio);
>>>> int split_folio_to_list(struct folio *folio, struct list_head *list);
>>>> bool folio_split_supported(struct folio *folio, unsigned int new_order,
>>>> @@ -382,7 +383,7 @@ int folio_split(struct folio *folio, unsigned int new_order, struct page *page,
>>>> static inline int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
>>>> unsigned int new_order)
>>>> {
>>>> - return __split_huge_page_to_list_to_order(page, list, new_order, false);
>>>> + return __split_huge_page_to_list_to_order(page, list, new_order);
>>>> }
>>>> static inline int split_huge_page_to_order(struct page *page, unsigned int new_order)
>>>> {
>>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>>>> index 0184cd915f44..942bd8410c54 100644
>>>> --- a/mm/huge_memory.c
>>>> +++ b/mm/huge_memory.c
>>>> @@ -3747,7 +3747,6 @@ bool folio_split_supported(struct folio *folio, unsigned int new_order,
>>>> * @lock_at: a page within @folio to be left locked to caller
>>>> * @list: after-split folios will be put on it if non NULL
>>>> * @split_type: perform uniform split or not (non-uniform split)
>>>> - * @unmapped: The pages are already unmapped, they are migration entries.
>>>> *
>>>> * It calls __split_unmapped_folio() to perform uniform and non-uniform split.
>>>> * It is in charge of checking whether the split is supported or not and
>>>> @@ -3763,7 +3762,7 @@ bool folio_split_supported(struct folio *folio, unsigned int new_order,
>>>> */
>>>> static int __folio_split(struct folio *folio, unsigned int new_order,
>>>> struct page *split_at, struct page *lock_at,
>>>> - struct list_head *list, enum split_type split_type, bool unmapped)
>>>> + struct list_head *list, enum split_type split_type)
>>>
>>> Yeah, nice to see that go.
>>>
>>>> {
>>>> struct deferred_split *ds_queue;
>>>> XA_STATE(xas, &folio->mapping->i_pages, folio->index);
>>>> @@ -3809,14 +3808,12 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
>>>> * is taken to serialise against parallel split or collapse
>>>> * operations.
>>>> */
>>>> - if (!unmapped) {
>>>> - anon_vma = folio_get_anon_vma(folio);
>>>> - if (!anon_vma) {
>>>> - ret = -EBUSY;
>>>> - goto out;
>>>> - }
>>>> - anon_vma_lock_write(anon_vma);
>>>> + anon_vma = folio_get_anon_vma(folio);
>>>> + if (!anon_vma) {
>>>> + ret = -EBUSY;
>>>> + goto out;
>>>> }
>>>> + anon_vma_lock_write(anon_vma);
>>>> mapping = NULL;
>>>> } else {
>>>> unsigned int min_order;
>>>> @@ -3882,8 +3879,7 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
>>>> goto out_unlock;
>>>> }
>>>> - if (!unmapped)
>>>> - unmap_folio(folio);
>>>> + unmap_folio(folio);
>>>>
>>>
>>> Hm, I would have hoped that we could factor out the core logic and reuse it for the new helper, instead of duplicating code.
>>>
>>> Did you look into that?
>>>
>>>
>>
>> I did, I ended up with larger spaghetti, I was hoping to look it as a follow up
>> after the series with the mTHP changes and support (that is to be designed and
>> prototyped).
>
> Looking at it in more detail, the code duplication is not desired.
>
> We have to find a way to factor the existing code out and reuse it from any new function.
>
I came up with a helper, but that ends up with another boolean do_lru.
---
include/linux/huge_mm.h | 5 +-
mm/huge_memory.c | 336 +++++++++++++++++++++++-----------------
mm/migrate_device.c | 3 +-
3 files changed, 195 insertions(+), 149 deletions(-)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index e2e91aa1a042..44c09755bada 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -371,7 +371,8 @@ enum split_type {
bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins);
int __split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
- unsigned int new_order, bool unmapped);
+ unsigned int new_order);
+int split_unmapped_folio(struct folio *folio, unsigned int new_order);
int min_order_for_split(struct folio *folio);
int split_folio_to_list(struct folio *folio, struct list_head *list);
bool folio_split_supported(struct folio *folio, unsigned int new_order,
@@ -382,7 +383,7 @@ int folio_split(struct folio *folio, unsigned int new_order, struct page *page,
static inline int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
unsigned int new_order)
{
- return __split_huge_page_to_list_to_order(page, list, new_order, false);
+ return __split_huge_page_to_list_to_order(page, list, new_order);
}
static inline int split_huge_page_to_order(struct page *page, unsigned int new_order)
{
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0184cd915f44..534befe1b7aa 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3739,6 +3739,152 @@ bool folio_split_supported(struct folio *folio, unsigned int new_order,
return true;
}
+static int __folio_split_unmapped(struct folio *folio, unsigned int new_order,
+ struct page *split_at, struct xa_state *xas,
+ struct address_space *mapping, bool do_lru,
+ struct list_head *list, enum split_type split_type,
+ int extra_pins)
+{
+ struct folio *end_folio = folio_next(folio);
+ struct folio *new_folio, *next;
+ int old_order = folio_order(folio);
+ int nr_shmem_dropped = 0;
+ int ret = 0;
+ pgoff_t end = 0;
+ struct deferred_split *ds_queue;
+
+ /* Prevent deferred_split_scan() touching ->_refcount */
+ ds_queue = folio_split_queue_lock(folio);
+ if (folio_ref_freeze(folio, 1 + extra_pins)) {
+ struct swap_cluster_info *ci = NULL;
+ struct lruvec *lruvec;
+ int expected_refs;
+
+ if (old_order > 1) {
+ if (!list_empty(&folio->_deferred_list)) {
+ ds_queue->split_queue_len--;
+ /*
+ * Reinitialize page_deferred_list after removing the
+ * page from the split_queue, otherwise a subsequent
+ * split will see list corruption when checking the
+ * page_deferred_list.
+ */
+ list_del_init(&folio->_deferred_list);
+ }
+ if (folio_test_partially_mapped(folio)) {
+ folio_clear_partially_mapped(folio);
+ mod_mthp_stat(old_order,
+ MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
+ }
+ }
+ split_queue_unlock(ds_queue);
+ if (mapping) {
+ int nr = folio_nr_pages(folio);
+
+ if (folio_test_pmd_mappable(folio) &&
+ new_order < HPAGE_PMD_ORDER) {
+ if (folio_test_swapbacked(folio)) {
+ __lruvec_stat_mod_folio(folio,
+ NR_SHMEM_THPS, -nr);
+ } else {
+ __lruvec_stat_mod_folio(folio,
+ NR_FILE_THPS, -nr);
+ filemap_nr_thps_dec(mapping);
+ }
+ }
+ }
+
+ if (folio_test_swapcache(folio)) {
+ if (mapping) {
+ VM_WARN_ON_ONCE_FOLIO(mapping, folio);
+ return -EINVAL;
+ }
+
+ ci = swap_cluster_get_and_lock(folio);
+ }
+
+ /* lock lru list/PageCompound, ref frozen by page_ref_freeze */
+ if (do_lru)
+ lruvec = folio_lruvec_lock(folio);
+
+ ret = __split_unmapped_folio(folio, new_order, split_at, xas,
+ mapping, split_type);
+
+ /*
+ * Unfreeze after-split folios and put them back to the right
+ * list. @folio should be kept frozon until page cache
+ * entries are updated with all the other after-split folios
+ * to prevent others seeing stale page cache entries.
+ * As a result, new_folio starts from the next folio of
+ * @folio.
+ */
+ for (new_folio = folio_next(folio); new_folio != end_folio;
+ new_folio = next) {
+ unsigned long nr_pages = folio_nr_pages(new_folio);
+
+ next = folio_next(new_folio);
+
+ zone_device_private_split_cb(folio, new_folio);
+
+ expected_refs = folio_expected_ref_count(new_folio) + 1;
+ folio_ref_unfreeze(new_folio, expected_refs);
+
+ if (do_lru)
+ lru_add_split_folio(folio, new_folio, lruvec, list);
+
+ /*
+ * Anonymous folio with swap cache.
+ * NOTE: shmem in swap cache is not supported yet.
+ */
+ if (ci) {
+ __swap_cache_replace_folio(ci, folio, new_folio);
+ continue;
+ }
+
+ /* Anonymous folio without swap cache */
+ if (!mapping)
+ continue;
+
+ /* Add the new folio to the page cache. */
+ if (new_folio->index < end) {
+ __xa_store(&mapping->i_pages, new_folio->index,
+ new_folio, 0);
+ continue;
+ }
+
+ /* Drop folio beyond EOF: ->index >= end */
+ if (shmem_mapping(mapping))
+ nr_shmem_dropped += nr_pages;
+ else if (folio_test_clear_dirty(new_folio))
+ folio_account_cleaned(
+ new_folio, inode_to_wb(mapping->host));
+ __filemap_remove_folio(new_folio, NULL);
+ folio_put_refs(new_folio, nr_pages);
+ }
+
+ zone_device_private_split_cb(folio, NULL);
+ /*
+ * Unfreeze @folio only after all page cache entries, which
+ * used to point to it, have been updated with new folios.
+ * Otherwise, a parallel folio_try_get() can grab @folio
+ * and its caller can see stale page cache entries.
+ */
+ expected_refs = folio_expected_ref_count(folio) + 1;
+ folio_ref_unfreeze(folio, expected_refs);
+
+ if (do_lru)
+ unlock_page_lruvec(lruvec);
+
+ if (ci)
+ swap_cluster_unlock(ci);
+ } else {
+ split_queue_unlock(ds_queue);
+ return -EAGAIN;
+ }
+
+ return 0;
+}
+
/**
* __folio_split() - split a folio at @split_at to a @new_order folio
* @folio: folio to split
@@ -3747,7 +3893,6 @@ bool folio_split_supported(struct folio *folio, unsigned int new_order,
* @lock_at: a page within @folio to be left locked to caller
* @list: after-split folios will be put on it if non NULL
* @split_type: perform uniform split or not (non-uniform split)
- * @unmapped: The pages are already unmapped, they are migration entries.
*
* It calls __split_unmapped_folio() to perform uniform and non-uniform split.
* It is in charge of checking whether the split is supported or not and
@@ -3763,9 +3908,8 @@ bool folio_split_supported(struct folio *folio, unsigned int new_order,
*/
static int __folio_split(struct folio *folio, unsigned int new_order,
struct page *split_at, struct page *lock_at,
- struct list_head *list, enum split_type split_type, bool unmapped)
+ struct list_head *list, enum split_type split_type)
{
- struct deferred_split *ds_queue;
XA_STATE(xas, &folio->mapping->i_pages, folio->index);
struct folio *end_folio = folio_next(folio);
bool is_anon = folio_test_anon(folio);
@@ -3809,14 +3953,12 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
* is taken to serialise against parallel split or collapse
* operations.
*/
- if (!unmapped) {
- anon_vma = folio_get_anon_vma(folio);
- if (!anon_vma) {
- ret = -EBUSY;
- goto out;
- }
- anon_vma_lock_write(anon_vma);
+ anon_vma = folio_get_anon_vma(folio);
+ if (!anon_vma) {
+ ret = -EBUSY;
+ goto out;
}
+ anon_vma_lock_write(anon_vma);
mapping = NULL;
} else {
unsigned int min_order;
@@ -3882,8 +4024,7 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
goto out_unlock;
}
- if (!unmapped)
- unmap_folio(folio);
+ unmap_folio(folio);
/* block interrupt reentry in xa_lock and spinlock */
local_irq_disable();
@@ -3900,142 +4041,14 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
}
}
- /* Prevent deferred_split_scan() touching ->_refcount */
- ds_queue = folio_split_queue_lock(folio);
- if (folio_ref_freeze(folio, 1 + extra_pins)) {
- struct swap_cluster_info *ci = NULL;
- struct lruvec *lruvec;
- int expected_refs;
-
- if (old_order > 1) {
- if (!list_empty(&folio->_deferred_list)) {
- ds_queue->split_queue_len--;
- /*
- * Reinitialize page_deferred_list after removing the
- * page from the split_queue, otherwise a subsequent
- * split will see list corruption when checking the
- * page_deferred_list.
- */
- list_del_init(&folio->_deferred_list);
- }
- if (folio_test_partially_mapped(folio)) {
- folio_clear_partially_mapped(folio);
- mod_mthp_stat(old_order,
- MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
- }
- }
- split_queue_unlock(ds_queue);
- if (mapping) {
- int nr = folio_nr_pages(folio);
-
- if (folio_test_pmd_mappable(folio) &&
- new_order < HPAGE_PMD_ORDER) {
- if (folio_test_swapbacked(folio)) {
- __lruvec_stat_mod_folio(folio,
- NR_SHMEM_THPS, -nr);
- } else {
- __lruvec_stat_mod_folio(folio,
- NR_FILE_THPS, -nr);
- filemap_nr_thps_dec(mapping);
- }
- }
- }
-
- if (folio_test_swapcache(folio)) {
- if (mapping) {
- VM_WARN_ON_ONCE_FOLIO(mapping, folio);
- ret = -EINVAL;
- goto fail;
- }
-
- ci = swap_cluster_get_and_lock(folio);
- }
-
- /* lock lru list/PageCompound, ref frozen by page_ref_freeze */
- lruvec = folio_lruvec_lock(folio);
-
- ret = __split_unmapped_folio(folio, new_order, split_at, &xas,
- mapping, split_type);
-
- /*
- * Unfreeze after-split folios and put them back to the right
- * list. @folio should be kept frozon until page cache
- * entries are updated with all the other after-split folios
- * to prevent others seeing stale page cache entries.
- * As a result, new_folio starts from the next folio of
- * @folio.
- */
- for (new_folio = folio_next(folio); new_folio != end_folio;
- new_folio = next) {
- unsigned long nr_pages = folio_nr_pages(new_folio);
-
- next = folio_next(new_folio);
-
- zone_device_private_split_cb(folio, new_folio);
-
- expected_refs = folio_expected_ref_count(new_folio) + 1;
- folio_ref_unfreeze(new_folio, expected_refs);
-
- if (!unmapped)
- lru_add_split_folio(folio, new_folio, lruvec, list);
-
- /*
- * Anonymous folio with swap cache.
- * NOTE: shmem in swap cache is not supported yet.
- */
- if (ci) {
- __swap_cache_replace_folio(ci, folio, new_folio);
- continue;
- }
-
- /* Anonymous folio without swap cache */
- if (!mapping)
- continue;
-
- /* Add the new folio to the page cache. */
- if (new_folio->index < end) {
- __xa_store(&mapping->i_pages, new_folio->index,
- new_folio, 0);
- continue;
- }
-
- /* Drop folio beyond EOF: ->index >= end */
- if (shmem_mapping(mapping))
- nr_shmem_dropped += nr_pages;
- else if (folio_test_clear_dirty(new_folio))
- folio_account_cleaned(
- new_folio, inode_to_wb(mapping->host));
- __filemap_remove_folio(new_folio, NULL);
- folio_put_refs(new_folio, nr_pages);
- }
-
- zone_device_private_split_cb(folio, NULL);
- /*
- * Unfreeze @folio only after all page cache entries, which
- * used to point to it, have been updated with new folios.
- * Otherwise, a parallel folio_try_get() can grab @folio
- * and its caller can see stale page cache entries.
- */
- expected_refs = folio_expected_ref_count(folio) + 1;
- folio_ref_unfreeze(folio, expected_refs);
-
- unlock_page_lruvec(lruvec);
-
- if (ci)
- swap_cluster_unlock(ci);
- } else {
- split_queue_unlock(ds_queue);
- ret = -EAGAIN;
- }
+ ret = __folio_split_unmapped(folio, new_order, split_at, &xas, mapping,
+ true, list, split_type, extra_pins);
fail:
if (mapping)
xas_unlock(&xas);
local_irq_enable();
- if (unmapped)
- return ret;
-
if (nr_shmem_dropped)
shmem_uncharge(mapping->host, nr_shmem_dropped);
@@ -4079,6 +4092,39 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
return ret;
}
+/*
+ * This function is a helper for splitting folios that have already been unmapped.
+ * The use case is that the device or the CPU can refuse to migrate THP pages in
+ * the middle of migration, due to allocation issues on either side
+ *
+ * The high level code is copied from __folio_split, since the pages are anonymous
+ * and are already isolated from the LRU, the code has been simplified to not
+ * burden __folio_split with unmapped sprinkled into the code.
+ *
+ * None of the split folios are unlocked
+ */
+int split_unmapped_folio(struct folio *folio, unsigned int new_order)
+{
+ int extra_pins, ret = 0;
+
+ VM_WARN_ON_FOLIO(folio_mapped(folio), folio);
+ VM_WARN_ON_ONCE_FOLIO(!folio_test_locked(folio), folio);
+ VM_WARN_ON_ONCE_FOLIO(!folio_test_large(folio), folio);
+
+ if (!can_split_folio(folio, 1, &extra_pins)) {
+ ret = -EAGAIN;
+ return ret;
+ }
+
+
+ local_irq_disable();
+ ret = __folio_split_unmapped(folio, new_order, &folio->page, NULL,
+ NULL, false, NULL, SPLIT_TYPE_UNIFORM,
+ extra_pins);
+ local_irq_enable();
+ return ret;
+}
+
/*
* This function splits a large folio into smaller folios of order @new_order.
* @page can point to any page of the large folio to split. The split operation
@@ -4127,12 +4173,12 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
* with the folio. Splitting to order 0 is compatible with all folios.
*/
int __split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
- unsigned int new_order, bool unmapped)
+ unsigned int new_order)
{
struct folio *folio = page_folio(page);
return __folio_split(folio, new_order, &folio->page, page, list,
- SPLIT_TYPE_UNIFORM, unmapped);
+ SPLIT_TYPE_UNIFORM);
}
/**
@@ -4163,7 +4209,7 @@ int folio_split(struct folio *folio, unsigned int new_order,
struct page *split_at, struct list_head *list)
{
return __folio_split(folio, new_order, split_at, &folio->page, list,
- SPLIT_TYPE_NON_UNIFORM, false);
+ SPLIT_TYPE_NON_UNIFORM);
}
int min_order_for_split(struct folio *folio)
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index c50abbd32f21..23b7bd56177c 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -918,8 +918,7 @@ static int migrate_vma_split_unmapped_folio(struct migrate_vma *migrate,
folio_get(folio);
split_huge_pmd_address(migrate->vma, addr, true);
- ret = __split_huge_page_to_list_to_order(folio_page(folio, 0), NULL,
- 0, true);
+ ret = split_unmapped_folio(folio, 0);
if (ret)
return ret;
migrate->src[idx] &= ~MIGRATE_PFN_COMPOUND;
--
2.51.1
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