Re: [PATCH 1/5] mm: add PSI accounting around ->read_folio and ->readahead calls

Jens Axboe
2022-09-10T11:34:10Z

On 9/10/22 12:50 AM, Christoph Hellwig wrote:
> @@ -2390,8 +2392,13 @@ static int filemap_read_folio(struct file *file, filler_t filler,
> * fails.
> */
> folio_clear_error(folio);
> +
> /* Start the actual read. The read will unlock the page. */
> + if (unlikely(workingset))
> + psi_memstall_enter(&pflags);
> error = filler(file, folio);
> + if (unlikely(workingset))
> + psi_memstall_leave(&pflags);
> if (error)
> return error;

I think this would read better as:

/* Start the actual read. The read will unlock the page. */
if (unlikely(workingset)) {
psi_memstall_enter(&pflags);
error = filler(file, folio);
psi_memstall_leave(&pflags);
} else {
error = filler(file, folio);
}
if (error)
return error;

--
Jens Axboe