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Date:   Tue, 3 Aug 2021 12:36:18 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Yu Zhao <yuzhao@google.com>
Cc:     linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        Hugh Dickins <hughd@google.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Yang Shi <shy828301@gmail.com>, Zi Yan <ziy@nvidia.com>,
        linux-kernel@vger.kernel.org, Shuang Zhai <zhais@google.com>
Subject: Re: [PATCH 3/3] mm: don't remap clean subpages when splitting
 isolated thp
Message-ID: <YQkqMhGsra8YCVoU@casper.infradead.org>
References: <20210731063938.1391602-1-yuzhao@google.com>
 <20210731063938.1391602-4-yuzhao@google.com>
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On Sat, Jul 31, 2021 at 12:39:38AM -0600, Yu Zhao wrote:
> +++ b/include/linux/rmap.h
> @@ -243,7 +243,7 @@ int page_mkclean(struct page *);
>   */
>  void page_mlock(struct page *page);
>  
> -void remove_migration_ptes(struct page *old, struct page *new, bool locked);
> +void remove_migration_ptes(struct page *old, struct page *new, bool locked, bool unmap_clean);

I'm not a big fan of 'bool, bool'.  Could we use a flag word instead?

#define MIGRATE_REMOVE_LOCKED	1
#define MIGRATE_UNMAP_CLEAN	2