From: Huang Ying <ying.huang@intel.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Huang Ying <ying.huang@intel.com>,
Alistair Popple <apopple@nvidia.com>, Zi Yan <ziy@nvidia.com>,
Yang Shi <shy828301@gmail.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Oscar Salvador <osalvador@suse.de>,
Matthew Wilcox <willy@infradead.org>,
Bharata B Rao <bharata@amd.com>, Xin Hao <xhao@linux.alibaba.com>,
Minchan Kim <minchan@kernel.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Hyeonggon Yoo <42.hyeyoo@gmail.com>
Subject: [PATCH -v5 9/9] migrate_pages: move THP/hugetlb migration support check to simplify code
Date: Mon, 13 Feb 2023 20:34:44 +0800 [thread overview]
Message-ID: <20230213123444.155149-10-ying.huang@intel.com> (raw)
In-Reply-To: <20230213123444.155149-1-ying.huang@intel.com>
This is a code cleanup patch, no functionality change is expected.
After the change, the line number reduces especially in the long
migrate_pages_batch().
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: 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: 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>
---
mm/migrate.c | 83 +++++++++++++++++++++++-----------------------------
1 file changed, 36 insertions(+), 47 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index 2fa420e4f68c..ef68a1aff35c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1117,9 +1117,6 @@ static int migrate_folio_unmap(new_page_t get_new_page, free_page_t put_new_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);
@@ -1380,16 +1377,6 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
struct anon_vma *anon_vma = NULL;
struct address_space *mapping = NULL;
- /*
- * Migratability of hugepages depends on architectures and their size.
- * This check is necessary because some callers of hugepage migration
- * like soft offline and memory hotremove don't walk through page
- * tables or check whether the hugepage is pmd-based or not before
- * kicking migration.
- */
- if (!hugepage_migration_supported(page_hstate(hpage)))
- return -ENOSYS;
-
if (folio_ref_count(src) == 1) {
/* page was freed from under us. So we are done. */
folio_putback_active_hugetlb(src);
@@ -1556,6 +1543,20 @@ static int migrate_hugetlbs(struct list_head *from, new_page_t get_new_page,
cond_resched();
+ /*
+ * Migratability of hugepages depends on architectures and
+ * their size. This check is necessary because some callers
+ * of hugepage migration like soft offline and memory
+ * hotremove don't walk through page tables or check whether
+ * the hugepage is pmd-based or not before kicking migration.
+ */
+ if (!hugepage_migration_supported(folio_hstate(folio))) {
+ nr_failed++;
+ stats->nr_failed_pages += nr_pages;
+ list_move_tail(&folio->lru, ret_folios);
+ continue;
+ }
+
rc = unmap_and_move_huge_page(get_new_page,
put_new_page, private,
&folio->page, pass > 2, mode,
@@ -1565,16 +1566,9 @@ static int migrate_hugetlbs(struct list_head *from, new_page_t get_new_page,
* Success: hugetlb folio will be put back
* -EAGAIN: stay on the from list
* -ENOMEM: stay on the from list
- * -ENOSYS: stay on the from list
* Other errno: put on ret_folios list
*/
switch(rc) {
- case -ENOSYS:
- /* Hugetlb migration is unsupported */
- nr_failed++;
- stats->nr_failed_pages += nr_pages;
- list_move_tail(&folio->lru, ret_folios);
- break;
case -ENOMEM:
/*
* When memory is low, don't bother to try to migrate
@@ -1664,6 +1658,28 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page,
cond_resched();
+ /*
+ * Large folio migration might be unsupported or
+ * the allocation might be failed so we should retry
+ * on the same folio with the large folio split
+ * to normal folios.
+ *
+ * Split folios are put in split_folios, and
+ * we will migrate them after the rest of the
+ * list is processed.
+ */
+ if (!thp_migration_supported() && is_thp) {
+ nr_large_failed++;
+ stats->nr_thp_failed++;
+ if (!try_split_folio(folio, &split_folios)) {
+ stats->nr_thp_split++;
+ continue;
+ }
+ stats->nr_failed_pages += nr_pages;
+ list_move_tail(&folio->lru, ret_folios);
+ continue;
+ }
+
rc = migrate_folio_unmap(get_new_page, put_new_page, private,
folio, &dst, pass > 2, avoid_force_lock,
mode, reason, ret_folios);
@@ -1675,36 +1691,9 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page,
* -EAGAIN: stay on the from list
* -EDEADLOCK: stay on the from list
* -ENOMEM: stay on the from list
- * -ENOSYS: stay on the from list
* Other errno: put on ret_folios list
*/
switch(rc) {
- /*
- * Large folio migration might be unsupported or
- * the allocation could've failed so we should retry
- * on the same folio with the large folio split
- * to normal folios.
- *
- * Split folios are put in split_folios, and
- * we will migrate them after the rest of the
- * list is processed.
- */
- case -ENOSYS:
- /* Large folio migration is unsupported */
- if (is_large) {
- nr_large_failed++;
- stats->nr_thp_failed += is_thp;
- if (!try_split_folio(folio, &split_folios)) {
- stats->nr_thp_split += is_thp;
- break;
- }
- } else if (!no_split_folio_counting) {
- nr_failed++;
- }
-
- stats->nr_failed_pages += nr_pages;
- list_move_tail(&folio->lru, ret_folios);
- break;
case -ENOMEM:
/*
* When memory is low, don't bother to try to migrate
--
2.35.1
next prev parent reply other threads:[~2023-02-13 12:35 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-13 12:34 [PATCH -v5 0/9] migrate_pages(): batch TLB flushing Huang Ying
2023-02-13 12:34 ` [PATCH -v5 1/9] migrate_pages: organize stats with struct migrate_pages_stats Huang Ying
2023-02-13 12:34 ` [PATCH -v5 2/9] migrate_pages: separate hugetlb folios migration Huang Ying
2023-02-13 12:34 ` [PATCH -v5 3/9] migrate_pages: restrict number of pages to migrate in batch Huang Ying
2023-02-13 12:34 ` [PATCH -v5 4/9] migrate_pages: split unmap_and_move() to _unmap() and _move() Huang Ying
2023-02-13 12:34 ` [PATCH -v5 5/9] migrate_pages: batch _unmap and _move Huang Ying
2023-02-13 12:34 ` [PATCH -v5 6/9] migrate_pages: move migrate_folio_unmap() Huang Ying
2023-02-13 12:34 ` [PATCH -v5 7/9] migrate_pages: share more code between _unmap and _move Huang Ying
2023-02-13 12:34 ` [PATCH -v5 8/9] migrate_pages: batch flushing TLB Huang Ying
2023-02-13 12:34 ` Huang Ying [this message]
2023-02-17 21:47 ` [PATCH -v5 0/9] migrate_pages(): batch TLB flushing Hugh Dickins
2023-02-20 9:28 ` Huang, Ying
2023-02-21 2:48 ` Hugh Dickins
2023-02-21 3:34 ` Huang, Ying
2023-02-21 22:15 ` Hugh Dickins
2023-02-21 4:30 ` Matthew Wilcox
2023-02-21 4:38 ` Huang, Ying
2023-02-21 14:04 ` Huang, Ying
2023-02-21 22:25 ` Hugh Dickins
2023-02-22 1:02 ` Huang, Ying
2023-02-27 11:06 ` Jan Kara
2023-02-28 1:13 ` Huang, Ying
2023-02-28 5:59 ` Hugh Dickins
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