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

Eric Biggers
2020-03-20T17:37:39Z

On Fri, Mar 20, 2020 at 07:22:26AM -0700, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
>
> Use the new readahead operation in ext4
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> Reviewed-by: William Kucharski <william.kucharski@oracle.com>
> ---
> 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@google.com>

> + 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