Re: [PATCH] block/psi: make PSI annotations of submit_bio only work for file pages

[Christoph Hellwig]

> @@ -1035,8 +1035,9 @@ void __bio_add_page(struct bio *bio, struct page *page,
>  	bio->bi_iter.bi_size += len;
>  	bio->bi_vcnt++;
>  
> -	if (!bio_flagged(bio, BIO_WORKINGSET) && unlikely(PageWorkingset(page)))
> -		bio_set_flag(bio, BIO_WORKINGSET);
> +	if (!bio_flagged(bio, BIO_WORKINGSET_FILE) &&
> +	    unlikely(PageWorkingset(page)) && !PageSwapBacked(page))
> +		bio_set_flag(bio, BIO_WORKINGSET_FILE);

This needs to go out of the block I/O fast path, not grow even more
checks.