On 2024/8/22 15:20, Miaohe Lin wrote:
On 2024/8/17 16:49, Kefeng Wang wrote:
Use the isolate_folio_to_list() to unify hugetlb/LRU/non-LRU
folio isolation, which cleanup code a bit and save a few calls
to compound_head().
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
mm/memory_hotplug.c | 45 +++++++++++++++++----------------------------
1 file changed, 17 insertions(+), 28 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 02a0d4fbc3fe..cc9c16db2f8c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1773,14 +1773,14 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pfn;
- struct page *page;
LIST_HEAD(source);
+ struct folio *folio;
static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
for (pfn = start_pfn; pfn < end_pfn; pfn++) {
- struct folio *folio;
- bool isolated;
+ struct page *page;
+ bool huge;
if (!pfn_valid(pfn))
continue;
@@ -1812,34 +1812,22 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
continue;
}
- if (folio_test_hugetlb(folio)) {
- isolate_hugetlb(folio, &source);
- continue;
+ huge = folio_test_hugetlb(folio);
+ if (!huge) {
+ folio = folio_get_nontail_page(page);
+ if (!folio)
+ continue;
}
- if (!get_page_unless_zero(page))
Does page always equal to head? Page is used in most cases in this function and head is only used to calculate pfn.
If not, folio can not simply replace page?
Not very clear what your mean, no guarantee for page == head, that
is why we need use get_page_unless_zero or folio_get_nontail_page to get
the folio, then try to isolate folio, since we only migrate the wholo
folio, I don't know why we can't convert page to folio here.
- continue;
- /*
- * We can skip free pages. And we can deal with pages on
- * LRU and non-lru movable pages.
- */
- if (PageLRU(page))
I think this check is incorrect. We should check __PageMovable(page) instead. So this patch
fixes this issue too.
Thanks.
.
