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Message-ID: <f06e4a39-39e7-44de-dbc8-dc82ead37047@redhat.com>
Date:   Fri, 29 Apr 2022 12:08:56 +0200
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Subject: Re: [PATCH v2 3/4] mm/migration: return errno when isolate_huge_page
 failed
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To:     Miaohe Lin <linmiaohe@huawei.com>, akpm@linux-foundation.org,
        mike.kravetz@oracle.com, naoya.horiguchi@nec.com
Cc:     ying.huang@intel.com, hch@lst.de, dhowells@redhat.com,
        cl@linux.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20220425132723.34824-1-linmiaohe@huawei.com>
 <20220425132723.34824-4-linmiaohe@huawei.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20220425132723.34824-4-linmiaohe@huawei.com>
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On 25.04.22 15:27, Miaohe Lin wrote:
> We might fail to isolate huge page due to e.g. the page is under migration
> which cleared HPageMigratable. So we should return -EBUSY in this case
> rather than always return 1 which could confuse the user. Also we make
> the prototype of isolate_huge_page consistent with isolate_lru_page to
> improve the readability.
> 
> Fixes: e8db67eb0ded ("mm: migrate: move_pages() supports thp migration")

If this is a fix, what's the runtime effect of it?

You state "could confuse", which doesn't indicate an actual BUG to me.


-- 
Thanks,

David / dhildenb