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Date:   Wed, 10 Mar 2021 08:43:21 +0000
From:   Christoph Hellwig <hch@infradead.org>
To:     "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-bcache@vger.kernel.org, linux-nvdimm@lists.01.org,
        linux-scsi@vger.kernel.org
Subject: Re: [PATCH v2] include: Remove pagemap.h from blkdev.h
Message-ID: <20210310084321.GA682482@infradead.org>
References: <20210309195747.283796-1-willy@infradead.org>
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On Tue, Mar 09, 2021 at 07:57:47PM +0000, Matthew Wilcox (Oracle) wrote:
> My UEK-derived config has 1030 files depending on pagemap.h before
> this change.  Afterwards, just 326 files need to be rebuilt when I
> touch pagemap.h.  I think blkdev.h is probably included too widely,
> but untangling that dependency is harder and this solves my problem.
> x86 allmodconfig builds, but there may be implicit include problems
> on other architectures.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
> v2: Fix CONFIG_SWAP=n implicit use of pagemap.h by swap.h.  Increases
>     the number of files from 240, but that's still a big win -- 68%
>     reduction instead of 77%.

Looks good.  I suspect blkdev.h also has penty of other includes that
aren't needed either..

Reviewed-by: Christoph Hellwig <hch@lst.de>