Re: [PATCH v9 20/25] ext4: Convert from readpages to readahead

[Eric Biggers]

On Fri, Mar 20, 2020 at 07:22:26AM -0700, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
> 
> Use the new readahead operation in ext4
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx>
> ---
>  fs/ext4/ext4.h     |  3 +--
>  fs/ext4/inode.c    | 21 +++++++++------------
>  fs/ext4/readpage.c | 22 ++++++++--------------
>  3 files changed, 18 insertions(+), 28 deletions(-)
> 

Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>

> +		if (rac) {
> +			page = readahead_page(rac);
>  			prefetchw(&page->flags);
> -			list_del(&page->lru);
> -			if (add_to_page_cache_lru(page, mapping, page->index,
> -				  readahead_gfp_mask(mapping)))
> -				goto next_page;
>  		}

Maybe the prefetchw(&page->flags) should be included in readahead_page()?
Most of the callers do it.

- Eric