On Thu, May 08, 2025 at 07:47:44AM +0200, Christoph Hellwig wrote: > +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c > @@ -318,7 +318,7 @@ void __shmem_writeback(size_t size, struct address_space *mapping) > if (folio_mapped(folio)) > folio_redirty_for_writepage(&wbc, folio); > else > - error = shmem_writeout(folio, &wbc); > + error = shmem_writeout(folio, NULL, NULL); > } > } This got me to look at why we need to keep wbc in __shmem_writeback(). We only have it because folio_redirty_for_writepage() needs it. And folio_redirty_for_writepage() only needs it because it updates pages_skipped. I'm not quite sure if we can simply call filemap_dirty_folio() here or whether mapping_can_writeback() is true for shmem and we need to do all the other things -- in which case we could just change that one line to if (wbc) wbc->pages_skipped += nr; and then pass NULL to folio_redirty_for_writepage() and delete the wbc on the stack.
