migrate_pages: share more code between _unmap and _move
This is a code cleanup patch to reduce the duplicated code between the _unmap and _move stages of migrate_pages(). No functionality change is expected. Link: https://lkml.kernel.org/r/20230213123444.155149-8-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Bharata B Rao <bharata@amd.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Xin Hao <xhao@linux.alibaba.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Huang Ying
Andrew Morton
parent
80562ba0d8
commit
ebe75e4751
189
mm/migrate.c
189
mm/migrate.c
@ -1055,6 +1055,7 @@ static void __migrate_folio_extract(struct folio *dst,
|
||||
static void migrate_folio_undo_src(struct folio *src,
|
||||
int page_was_mapped,
|
||||
struct anon_vma *anon_vma,
|
||||
bool locked,
|
||||
struct list_head *ret)
|
||||
{
|
||||
if (page_was_mapped)
|
||||
@ -1062,15 +1063,19 @@ static void migrate_folio_undo_src(struct folio *src,
|
||||
/* Drop an anon_vma reference if we took one */
|
||||
if (anon_vma)
|
||||
put_anon_vma(anon_vma);
|
||||
if (locked)
|
||||
folio_unlock(src);
|
||||
if (ret)
|
||||
list_move_tail(&src->lru, ret);
|
||||
}
|
||||
|
||||
/* Restore the destination folio to the original state upon failure */
|
||||
static void migrate_folio_undo_dst(struct folio *dst,
|
||||
bool locked,
|
||||
free_page_t put_new_page,
|
||||
unsigned long private)
|
||||
{
|
||||
if (locked)
|
||||
folio_unlock(dst);
|
||||
if (put_new_page)
|
||||
put_new_page(&dst->page, private);
|
||||
@ -1096,13 +1101,42 @@ static void migrate_folio_done(struct folio *src,
|
||||
folio_put(src);
|
||||
}
|
||||
|
||||
static int __migrate_folio_unmap(struct folio *src, struct folio *dst, int force,
|
||||
bool avoid_force_lock, enum migrate_mode mode)
|
||||
/* Obtain the lock on page, remove all ptes. */
|
||||
static int migrate_folio_unmap(new_page_t get_new_page, free_page_t put_new_page,
|
||||
unsigned long private, struct folio *src,
|
||||
struct folio **dstp, int force, bool avoid_force_lock,
|
||||
enum migrate_mode mode, enum migrate_reason reason,
|
||||
struct list_head *ret)
|
||||
{
|
||||
struct folio *dst;
|
||||
int rc = -EAGAIN;
|
||||
struct page *newpage = NULL;
|
||||
int page_was_mapped = 0;
|
||||
struct anon_vma *anon_vma = NULL;
|
||||
bool is_lru = !__PageMovable(&src->page);
|
||||
bool locked = false;
|
||||
bool dst_locked = false;
|
||||
|
||||
if (!thp_migration_supported() && folio_test_transhuge(src))
|
||||
return -ENOSYS;
|
||||
|
||||
if (folio_ref_count(src) == 1) {
|
||||
/* Folio was freed from under us. So we are done. */
|
||||
folio_clear_active(src);
|
||||
folio_clear_unevictable(src);
|
||||
/* free_pages_prepare() will clear PG_isolated. */
|
||||
list_del(&src->lru);
|
||||
migrate_folio_done(src, reason);
|
||||
return MIGRATEPAGE_SUCCESS;
|
||||
}
|
||||
|
||||
newpage = get_new_page(&src->page, private);
|
||||
if (!newpage)
|
||||
return -ENOMEM;
|
||||
dst = page_folio(newpage);
|
||||
*dstp = dst;
|
||||
|
||||
dst->private = NULL;
|
||||
|
||||
if (!folio_trylock(src)) {
|
||||
if (!force || mode == MIGRATE_ASYNC)
|
||||
@ -1137,6 +1171,7 @@ static int __migrate_folio_unmap(struct folio *src, struct folio *dst, int force
|
||||
|
||||
folio_lock(src);
|
||||
}
|
||||
locked = true;
|
||||
|
||||
if (folio_test_writeback(src)) {
|
||||
/*
|
||||
@ -1151,10 +1186,10 @@ static int __migrate_folio_unmap(struct folio *src, struct folio *dst, int force
|
||||
break;
|
||||
default:
|
||||
rc = -EBUSY;
|
||||
goto out_unlock;
|
||||
goto out;
|
||||
}
|
||||
if (!force)
|
||||
goto out_unlock;
|
||||
goto out;
|
||||
folio_wait_writeback(src);
|
||||
}
|
||||
|
||||
@ -1184,7 +1219,8 @@ static int __migrate_folio_unmap(struct folio *src, struct folio *dst, int force
|
||||
* This is much like races on refcount of oldpage: just don't BUG().
|
||||
*/
|
||||
if (unlikely(!folio_trylock(dst)))
|
||||
goto out_unlock;
|
||||
goto out;
|
||||
dst_locked = true;
|
||||
|
||||
if (unlikely(!is_lru)) {
|
||||
__migrate_folio_record(dst, page_was_mapped, anon_vma);
|
||||
@ -1206,7 +1242,7 @@ static int __migrate_folio_unmap(struct folio *src, struct folio *dst, int force
|
||||
if (!src->mapping) {
|
||||
if (folio_test_private(src)) {
|
||||
try_to_free_buffers(src);
|
||||
goto out_unlock_both;
|
||||
goto out;
|
||||
}
|
||||
} else if (folio_mapped(src)) {
|
||||
/* Establish migration ptes */
|
||||
@ -1221,73 +1257,25 @@ static int __migrate_folio_unmap(struct folio *src, struct folio *dst, int force
|
||||
return MIGRATEPAGE_UNMAP;
|
||||
}
|
||||
|
||||
if (page_was_mapped)
|
||||
remove_migration_ptes(src, src, false);
|
||||
|
||||
out_unlock_both:
|
||||
folio_unlock(dst);
|
||||
out_unlock:
|
||||
/* Drop an anon_vma reference if we took one */
|
||||
if (anon_vma)
|
||||
put_anon_vma(anon_vma);
|
||||
folio_unlock(src);
|
||||
out:
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
/* Obtain the lock on page, remove all ptes. */
|
||||
static int migrate_folio_unmap(new_page_t get_new_page, free_page_t put_new_page,
|
||||
unsigned long private, struct folio *src,
|
||||
struct folio **dstp, int force, bool avoid_force_lock,
|
||||
enum migrate_mode mode, enum migrate_reason reason,
|
||||
struct list_head *ret)
|
||||
{
|
||||
struct folio *dst;
|
||||
int rc = MIGRATEPAGE_UNMAP;
|
||||
struct page *newpage = NULL;
|
||||
|
||||
if (!thp_migration_supported() && folio_test_transhuge(src))
|
||||
return -ENOSYS;
|
||||
|
||||
if (folio_ref_count(src) == 1) {
|
||||
/* Folio was freed from under us. So we are done. */
|
||||
folio_clear_active(src);
|
||||
folio_clear_unevictable(src);
|
||||
/* free_pages_prepare() will clear PG_isolated. */
|
||||
list_del(&src->lru);
|
||||
migrate_folio_done(src, reason);
|
||||
return MIGRATEPAGE_SUCCESS;
|
||||
}
|
||||
|
||||
newpage = get_new_page(&src->page, private);
|
||||
if (!newpage)
|
||||
return -ENOMEM;
|
||||
dst = page_folio(newpage);
|
||||
*dstp = dst;
|
||||
|
||||
dst->private = NULL;
|
||||
rc = __migrate_folio_unmap(src, dst, force, avoid_force_lock, mode);
|
||||
if (rc == MIGRATEPAGE_UNMAP)
|
||||
return rc;
|
||||
|
||||
/*
|
||||
* A folio that has not been unmapped will be restored to
|
||||
* right list unless we want to retry.
|
||||
*/
|
||||
if (rc != -EAGAIN && rc != -EDEADLOCK)
|
||||
list_move_tail(&src->lru, ret);
|
||||
if (rc == -EAGAIN || rc == -EDEADLOCK)
|
||||
ret = NULL;
|
||||
|
||||
if (put_new_page)
|
||||
put_new_page(&dst->page, private);
|
||||
else
|
||||
folio_put(dst);
|
||||
migrate_folio_undo_src(src, page_was_mapped, anon_vma, locked, ret);
|
||||
migrate_folio_undo_dst(dst, dst_locked, put_new_page, private);
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
static int __migrate_folio_move(struct folio *src, struct folio *dst,
|
||||
enum migrate_mode mode)
|
||||
/* Migrate the folio to the newly allocated folio in dst. */
|
||||
static int migrate_folio_move(free_page_t put_new_page, unsigned long private,
|
||||
struct folio *src, struct folio *dst,
|
||||
enum migrate_mode mode, enum migrate_reason reason,
|
||||
struct list_head *ret)
|
||||
{
|
||||
int rc;
|
||||
int page_was_mapped = 0;
|
||||
@ -1300,12 +1288,8 @@ static int __migrate_folio_move(struct folio *src, struct folio *dst,
|
||||
list_del(&dst->lru);
|
||||
|
||||
rc = move_to_new_folio(dst, src, mode);
|
||||
|
||||
if (rc == -EAGAIN) {
|
||||
list_add(&dst->lru, prev);
|
||||
__migrate_folio_record(dst, page_was_mapped, anon_vma);
|
||||
return rc;
|
||||
}
|
||||
if (rc)
|
||||
goto out;
|
||||
|
||||
if (unlikely(!is_lru))
|
||||
goto out_unlock_both;
|
||||
@ -1319,70 +1303,49 @@ static int __migrate_folio_move(struct folio *src, struct folio *dst,
|
||||
* unsuccessful, and other cases when a page has been temporarily
|
||||
* isolated from the unevictable LRU: but this case is the easiest.
|
||||
*/
|
||||
if (rc == MIGRATEPAGE_SUCCESS) {
|
||||
folio_add_lru(dst);
|
||||
if (page_was_mapped)
|
||||
lru_add_drain();
|
||||
}
|
||||
|
||||
if (page_was_mapped)
|
||||
remove_migration_ptes(src,
|
||||
rc == MIGRATEPAGE_SUCCESS ? dst : src, false);
|
||||
remove_migration_ptes(src, dst, false);
|
||||
|
||||
out_unlock_both:
|
||||
folio_unlock(dst);
|
||||
/* Drop an anon_vma reference if we took one */
|
||||
if (anon_vma)
|
||||
put_anon_vma(anon_vma);
|
||||
folio_unlock(src);
|
||||
set_page_owner_migrate_reason(&dst->page, reason);
|
||||
/*
|
||||
* If migration is successful, decrease refcount of dst,
|
||||
* which will not free the page because new page owner increased
|
||||
* refcounter.
|
||||
*/
|
||||
if (rc == MIGRATEPAGE_SUCCESS)
|
||||
folio_put(dst);
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
/* Migrate the folio to the newly allocated folio in dst. */
|
||||
static int migrate_folio_move(free_page_t put_new_page, unsigned long private,
|
||||
struct folio *src, struct folio *dst,
|
||||
enum migrate_mode mode, enum migrate_reason reason,
|
||||
struct list_head *ret)
|
||||
{
|
||||
int rc;
|
||||
|
||||
rc = __migrate_folio_move(src, dst, mode);
|
||||
if (rc == MIGRATEPAGE_SUCCESS)
|
||||
set_page_owner_migrate_reason(&dst->page, reason);
|
||||
|
||||
if (rc != -EAGAIN) {
|
||||
/*
|
||||
* A folio that has been migrated has all references
|
||||
* removed and will be freed. A folio that has not been
|
||||
* migrated will have kept its references and be restored.
|
||||
* A folio that has been migrated has all references removed
|
||||
* and will be freed.
|
||||
*/
|
||||
list_del(&src->lru);
|
||||
}
|
||||
|
||||
/*
|
||||
* If migration is successful, releases reference grabbed during
|
||||
* isolation. Otherwise, restore the folio to right list unless
|
||||
* we want to retry.
|
||||
*/
|
||||
if (rc == MIGRATEPAGE_SUCCESS) {
|
||||
/* Drop an anon_vma reference if we took one */
|
||||
if (anon_vma)
|
||||
put_anon_vma(anon_vma);
|
||||
folio_unlock(src);
|
||||
migrate_folio_done(src, reason);
|
||||
} else if (rc != -EAGAIN) {
|
||||
list_add_tail(&src->lru, ret);
|
||||
|
||||
if (put_new_page)
|
||||
put_new_page(&dst->page, private);
|
||||
else
|
||||
folio_put(dst);
|
||||
return rc;
|
||||
out:
|
||||
/*
|
||||
* A folio that has not been migrated will be restored to
|
||||
* right list unless we want to retry.
|
||||
*/
|
||||
if (rc == -EAGAIN) {
|
||||
list_add(&dst->lru, prev);
|
||||
__migrate_folio_record(dst, page_was_mapped, anon_vma);
|
||||
return rc;
|
||||
}
|
||||
|
||||
migrate_folio_undo_src(src, page_was_mapped, anon_vma, true, ret);
|
||||
migrate_folio_undo_dst(dst, true, put_new_page, private);
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
@ -1918,9 +1881,9 @@ out:
|
||||
|
||||
__migrate_folio_extract(dst, &page_was_mapped, &anon_vma);
|
||||
migrate_folio_undo_src(folio, page_was_mapped, anon_vma,
|
||||
ret_folios);
|
||||
true, ret_folios);
|
||||
list_del(&dst->lru);
|
||||
migrate_folio_undo_dst(dst, put_new_page, private);
|
||||
migrate_folio_undo_dst(dst, true, put_new_page, private);
|
||||
dst = dst2;
|
||||
dst2 = list_next_entry(dst, lru);
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user