From: Liu Shixin <liushixin2@huawei.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>
Cc: <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Liu Shixin <liushixin2@huawei.com>
Subject: [PATCH -next] mm, page_alloc: avoid page_to_pfn() in move_freepages()
Date: Tue, 23 Mar 2021 21:12:15 +0800 [thread overview]
Message-ID: <20210323131215.934472-1-liushixin2@huawei.com> (raw)
From: Kefeng Wang <wangkefeng.wang@huawei.com>
The start_pfn and end_pfn are already available in move_freepages_block(),
there is no need to go back and forth between page and pfn in move_freepages
and move_freepages_block, and pfn_valid_within() should validate pfn first
before touching the page.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
---
mm/page_alloc.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c53fe4fa10bf..ccfaa8158862 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2425,19 +2425,21 @@ static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
* boundary. If alignment is required, use move_freepages_block()
*/
static int move_freepages(struct zone *zone,
- struct page *start_page, struct page *end_page,
+ unsigned long start_pfn, unsigned long end_pfn,
int migratetype, int *num_movable)
{
struct page *page;
+ unsigned long pfn;
unsigned int order;
int pages_moved = 0;
- for (page = start_page; page <= end_page;) {
- if (!pfn_valid_within(page_to_pfn(page))) {
- page++;
+ for (pfn = start_pfn; pfn <= end_pfn;) {
+ if (!pfn_valid_within(pfn)) {
+ pfn++;
continue;
}
+ page = pfn_to_page(pfn);
if (!PageBuddy(page)) {
/*
* We assume that pages that could be isolated for
@@ -2447,8 +2449,7 @@ static int move_freepages(struct zone *zone,
if (num_movable &&
(PageLRU(page) || __PageMovable(page)))
(*num_movable)++;
-
- page++;
+ pfn++;
continue;
}
@@ -2458,7 +2459,7 @@ static int move_freepages(struct zone *zone,
order = buddy_order(page);
move_to_free_list(page, zone, order, migratetype);
- page += 1 << order;
+ pfn += 1 << order;
pages_moved += 1 << order;
}
@@ -2468,25 +2469,22 @@ static int move_freepages(struct zone *zone,
int move_freepages_block(struct zone *zone, struct page *page,
int migratetype, int *num_movable)
{
- unsigned long start_pfn, end_pfn;
- struct page *start_page, *end_page;
+ unsigned long start_pfn, end_pfn, pfn;
if (num_movable)
*num_movable = 0;
- start_pfn = page_to_pfn(page);
- start_pfn = start_pfn & ~(pageblock_nr_pages-1);
- start_page = pfn_to_page(start_pfn);
- end_page = start_page + pageblock_nr_pages - 1;
+ pfn = page_to_pfn(page);
+ start_pfn = pfn & ~(pageblock_nr_pages - 1);
end_pfn = start_pfn + pageblock_nr_pages - 1;
/* Do not cross zone boundaries */
if (!zone_spans_pfn(zone, start_pfn))
- start_page = page;
+ start_pfn = pfn;
if (!zone_spans_pfn(zone, end_pfn))
return 0;
- return move_freepages(zone, start_page, end_page, migratetype,
+ return move_freepages(zone, start_pfn, end_pfn, migratetype,
num_movable);
}
--
2.25.1
next reply other threads:[~2021-03-23 12:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-23 13:12 Liu Shixin [this message]
2021-03-23 12:54 ` [PATCH -next] mm, page_alloc: avoid page_to_pfn() in move_freepages() Matthew Wilcox
2021-03-27 3:34 ` Liu Shixin
2021-03-29 15:31 ` Vlastimil Babka
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