On Sun, Jul 25, 2021 at 10:18:34PM -0700, Andrew Morton wrote: > (Cc Matthew) > > (It might not be a folio thing at all - I haven't checked yet) Already fixed, thanks. folio_copy() had a cond_resched() in it, even if it was only copying a single page. Now it only calls cond_resched() if it's copying more than one page. We discussed this in the folio call on Friday, because we're leaving a bit of a landmine here for whoever tries to make multi-page folios work with buffer_heads. There's not much we can do about it for now; it'll just be one of the many problems to be dealt with. Hopefully filesystems will convert to iomap instead of trying to make buffer_heads support multiple pages.
