Re: [PATCH v2] include: Remove pagemap.h from blkdev.h

[Christoph Hellwig]

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@xxxxxxxxxxxxx>
> ---
> 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@xxxxxx>