From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org, linux-mm@kvack.org,
David Hildenbrand <david@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>,
"Michael S . Tsirkin" <mst@redhat.com>
Subject: [PATCH v1 1/6] mm/page_alloc: tweak comments in has_unmovable_pages()
Date: Tue, 30 Jun 2020 16:26:34 +0200 [thread overview]
Message-ID: <20200630142639.22770-2-david@redhat.com> (raw)
In-Reply-To: <20200630142639.22770-1-david@redhat.com>
Let's move the split comment regarding bootmem allocations and memory
holes, especially in the context of ZONE_MOVABLE, to the PageReserved()
check.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
mm/page_alloc.c | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 48eb0f1410d47..bd3ebf08f09b9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8207,14 +8207,6 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page,
unsigned long iter = 0;
unsigned long pfn = page_to_pfn(page);
- /*
- * TODO we could make this much more efficient by not checking every
- * page in the range if we know all of them are in MOVABLE_ZONE and
- * that the movable zone guarantees that pages are migratable but
- * the later is not the case right now unfortunatelly. E.g. movablecore
- * can still lead to having bootmem allocations in zone_movable.
- */
-
if (is_migrate_cma_page(page)) {
/*
* CMA allocations (alloc_contig_range) really need to mark
@@ -8233,6 +8225,12 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page,
page = pfn_to_page(pfn + iter);
+ /*
+ * Both, bootmem allocations and memory holes are marked
+ * PG_reserved and are unmovable. We can even have unmovable
+ * allocations inside ZONE_MOVABLE, for example when
+ * specifying "movable_core".
+ */
if (PageReserved(page))
return page;
@@ -8306,14 +8304,6 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page,
* it. But now, memory offline itself doesn't call
* shrink_node_slabs() and it still to be fixed.
*/
- /*
- * If the page is not RAM, page_count()should be 0.
- * we don't need more check. This is an _used_ not-movable page.
- *
- * The problematic thing here is PG_reserved pages. PG_reserved
- * is set to both of a memory hole page and a _used_ kernel
- * page at boot.
- */
return page;
}
return NULL;
--
2.26.2
next prev parent reply other threads:[~2020-06-30 14:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-30 14:26 [PATCH v1 0/6] mm / virtio-mem: support ZONE_MOVABLE David Hildenbrand
2020-06-30 14:26 ` David Hildenbrand [this message]
2020-07-28 13:48 ` [PATCH v1 1/6] mm/page_alloc: tweak comments in has_unmovable_pages() Baoquan He
2020-07-28 14:07 ` David Hildenbrand
2020-07-29 10:47 ` Baoquan He
2020-07-29 12:29 ` David Hildenbrand
2020-06-30 14:26 ` [PATCH v1 2/6] mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate() David Hildenbrand
2020-07-28 13:56 ` Baoquan He
2020-07-29 17:31 ` Mike Kravetz
2020-07-29 18:08 ` David Hildenbrand
2020-07-29 18:35 ` Mike Kravetz
2020-07-29 18:41 ` David Hildenbrand
2020-07-30 4:21 ` Pankaj Gupta
2020-06-30 14:26 ` [PATCH v1 3/6] mm/page_isolation: drop WARN_ON_ONCE() " David Hildenbrand
2020-07-29 13:24 ` Baoquan He
2020-07-29 13:37 ` David Hildenbrand
2020-07-29 14:05 ` Baoquan He
2020-06-30 14:26 ` [PATCH v1 4/6] mm/page_isolation: cleanup set_migratetype_isolate() David Hildenbrand
2020-07-29 14:06 ` Baoquan He
2020-07-30 4:31 ` Pankaj Gupta
2020-06-30 14:26 ` [PATCH v1 5/6] mm/page_alloc: restrict ZONE_MOVABLE optimization in has_unmovable_pages() to memory offlining David Hildenbrand
2020-07-27 12:23 ` David Hildenbrand
2020-06-30 14:26 ` [PATCH v1 6/6] virtio-mem: don't special-case ZONE_MOVABLE David Hildenbrand
2020-07-21 9:59 ` [PATCH v1 0/6] mm / virtio-mem: support ZONE_MOVABLE David Hildenbrand
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