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

Christoph Hellwig
2022-09-12T08:36:08Z

On Sat, Sep 10, 2022 at 05:34:02AM -0600, Jens Axboe wrote:
> > /* 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;

I had it both ways. For any non-trivial code in the conditionals I
tend to go with your version all the time. But for two times a single
lines both variants tends to suck, so I can live with either one.