From: Matthew Wilcox <willy@infradead.org>
To: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
akpm@linux-foundation.org, david@redhat.com, osalvador@suse.de
Subject: Re: [PATCH 2/2] mm/memory_hotplug: remove head page reference in scan_movable_pages()
Date: Mon, 23 Jan 2023 20:39:16 +0000 [thread overview]
Message-ID: <Y87wdBlxBrYjzADJ@casper.infradead.org> (raw)
In-Reply-To: <20230123202347.317065-2-sidhartha.kumar@oracle.com>
On Mon, Jan 23, 2023 at 12:23:47PM -0800, Sidhartha Kumar wrote:
> - if (!PageHuge(page))
> + folio = page_folio(page);
> + if (!folio_test_hugetlb(folio))
> continue;
> - head = compound_head(page);
> /*
> * This test is racy as we hold no reference or lock. The
> * hugetlb page could have been free'ed and head is no longer
Assuming the comment is correct, this patch is also unsafe.
next prev parent reply other threads:[~2023-01-23 20:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-23 20:23 [PATCH 1/2] mm/memory_hotplug: remove head page reference in do_migrate_range Sidhartha Kumar
2023-01-23 20:23 ` [PATCH 2/2] mm/memory_hotplug: remove head page reference in scan_movable_pages() Sidhartha Kumar
2023-01-23 20:39 ` Matthew Wilcox [this message]
2023-01-23 20:37 ` [PATCH 1/2] mm/memory_hotplug: remove head page reference in do_migrate_range Matthew Wilcox
2023-01-23 21:08 ` Sidhartha Kumar
2023-01-24 2:32 ` Matthew Wilcox
2023-01-24 10:17 ` David Hildenbrand
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