Commit 0efadf48 authored by Yisheng Xie's avatar Yisheng Xie Committed by Linus Torvalds

mm/hotplug: enable memory hotplug for non-lru movable pages

We had considered all of the non-lru pages as unmovable before commit
bda807d4 ("mm: migrate: support non-lru movable page migration").
But now some of non-lru pages like zsmalloc, virtio-balloon pages also
become movable.  So we can offline such blocks by using non-lru page
migration.

This patch straightforwardly adds non-lru migration code, which means
adding non-lru related code to the functions which scan over pfn and
collect pages to be migrated and isolate them before migration.
Signed-off-by: default avatarYisheng Xie <xieyisheng1@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 85fbe5d1
......@@ -1531,10 +1531,10 @@ int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
}
/*
* Scan pfn range [start,end) to find movable/migratable pages (LRU pages
* and hugepages). We scan pfn because it's much easier than scanning over
* linked list. This function returns the pfn of the first found movable
* page if it's found, otherwise 0.
* Scan pfn range [start,end) to find movable/migratable pages (LRU pages,
* non-lru movable pages and hugepages). We scan pfn because it's much
* easier than scanning over linked list. This function returns the pfn
* of the first found movable page if it's found, otherwise 0.
*/
static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
{
......@@ -1545,6 +1545,8 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
page = pfn_to_page(pfn);
if (PageLRU(page))
return pfn;
if (__PageMovable(page))
return pfn;
if (PageHuge(page)) {
if (page_huge_active(page))
return pfn;
......@@ -1621,21 +1623,25 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
if (!get_page_unless_zero(page))
continue;
/*
* We can skip free pages. And we can only deal with pages on
* LRU.
* We can skip free pages. And we can deal with pages on
* LRU and non-lru movable pages.
*/
if (PageLRU(page))
ret = isolate_lru_page(page);
else
ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE);
if (!ret) { /* Success */
put_page(page);
list_add_tail(&page->lru, &source);
move_pages--;
if (!__PageMovable(page))
inc_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page));
} else {
#ifdef CONFIG_DEBUG_VM
pr_alert("removing pfn %lx from LRU failed\n", pfn);
dump_page(page, "failed to remove from LRU");
pr_alert("failed to isolate pfn %lx\n", pfn);
dump_page(page, "isolation failed");
#endif
put_page(page);
/* Because we don't have big zone->lock. we should
......
......@@ -7227,8 +7227,9 @@ void *__init alloc_large_system_hash(const char *tablename,
* If @count is not zero, it is okay to include less @count unmovable pages
*
* PageLRU check without isolation or lru_lock could race so that
* MIGRATE_MOVABLE block might include unmovable pages. It means you can't
* expect this function should be exact.
* MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
* check without lock_page also may miss some movable non-lru pages at
* race condition. So you can't expect this function should be exact.
*/
bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
bool skip_hwpoisoned_pages)
......@@ -7284,6 +7285,9 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
if (skip_hwpoisoned_pages && PageHWPoison(page))
continue;
if (__PageMovable(page))
continue;
if (!PageLRU(page))
found++;
/*
......
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