Re: [PATCH 1/2] mm,swap: extract swap single page readahead into its own function

[Christoph Hellwig]

On Mon, Sep 21, 2020 at 10:01:47PM -0400, Rik van Riel wrote:
> +static struct page *swap_cluster_read_one(swp_entry_t entry,
> +		unsigned long offset, gfp_t gfp_mask,
> +		struct vm_area_struct *vma, unsigned long addr, bool readahead)
> +{
> +	bool page_allocated;
> +	struct page *page;
> +
> +	page =__read_swap_cache_async(swp_entry(swp_type(entry), offset),
> +				      gfp_mask, vma, addr, &page_allocated);

Missing whitespace after the "=".

> +	if (!page)
> +		return NULL;
> +	if (page_allocated) {
> +		swap_readpage(page, false);
> +		if (readahead) {
> +			SetPageReadahead(page);
> +			count_vm_event(SWAP_RA);
> +		}
> +	}
> +	put_page(page);
> +	return page;
> +}

I think swap_vma_readahead can be switched to your new helper
pretty trivially as well, as could many of the users of
read_swap_cache_async.