From: David Hildenbrand <david@redhat.com>
To: Muchun Song <songmuchun@bytedance.com>, akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/page_isolation: do not isolate the max order page
Date: Thu, 3 Dec 2020 17:27:07 +0100 [thread overview]
Message-ID: <ddd62925-fff5-4e0b-399a-ca1b70ac202b@redhat.com> (raw)
In-Reply-To: <20201202122114.75316-1-songmuchun@bytedance.com>
On 02.12.20 13:21, Muchun Song wrote:
> The max order page has no buddy page and never merge to other order.
> So isolating and then freeing it is pointless.
>
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>
> ---
> mm/page_isolation.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/page_isolation.c b/mm/page_isolation.c
> index a254e1f370a3..bddf788f45bf 100644
> --- a/mm/page_isolation.c
> +++ b/mm/page_isolation.c
> @@ -88,7 +88,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
> */
> if (PageBuddy(page)) {
> order = buddy_order(page);
> - if (order >= pageblock_order) {
> + if (order >= pageblock_order && order < MAX_ORDER - 1) {
> pfn = page_to_pfn(page);
> buddy_pfn = __find_buddy_pfn(pfn, order);
> buddy = page + (buddy_pfn - pfn);
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
prev parent reply other threads:[~2020-12-03 16:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 12:21 [PATCH] mm/page_isolation: do not isolate the max order page Muchun Song
2020-12-03 0:03 ` Vlastimil Babka
2020-12-03 2:43 ` [External] " Muchun Song
2020-12-03 15:49 ` Vlastimil Babka
2020-12-03 16:26 ` David Hildenbrand
2020-12-03 17:15 ` Vlastimil Babka
2020-12-03 17:48 ` David Hildenbrand
2020-12-03 19:24 ` David Hildenbrand
2020-12-03 16:27 ` David Hildenbrand [this message]
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