On Thu, May 26, 2022 at 02:16:34AM +0100, Matthew Wilcox wrote: > Bizarre this started showing up now. The recent patch was: > > - info->alloced += compound_nr(page); > - inode->i_blocks += BLOCKS_PER_PAGE << compound_order(page); > + info->alloced += folio_nr_pages(folio); > + inode->i_blocks += BLOCKS_PER_PAGE << folio_order(folio); > > so it could tell that compound_order() was small, but folio_order() > might be large? The old code also generates a warning on my test system. Smatch thinks both compound_order() and folio_order() are 0-255. I guess because of the "unsigned char compound_order;" in the struct page. regards, dan carpenter