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Date:   Thu, 4 Feb 2021 00:34:26 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Minchan Kim <minchan@kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [RFC] mm: fs: Invalidate BH LRU during page migration
Message-ID: <20210204003426.GC308988@casper.infradead.org>
References: <cover.1612248395.git.cgoldswo@codeaurora.org>
 <695193a165bf538f35de84334b4da2cc3544abe0.1612248395.git.cgoldswo@codeaurora.org>
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On Mon, Feb 01, 2021 at 10:55:47PM -0800, Chris Goldsworthy wrote:
> @@ -1289,6 +1289,8 @@ static inline void check_irqs_on(void)
>  #endif
>  }
>  
> +bool bh_migration_done = true;

What protects this global variable?  Or is there some subtle reason it
doesn't need protection, in which case, please put that in a comment.