On Mon, Jan 31, 2022 at 08:54:39PM +0000, Joao Martins wrote: > On 1/31/22 20:29, Matthew Wilcox wrote: > > Unless I am mistaken, you have to pass the compound head of the page > > which has the error to collect_procs(). Am I mistaken? > > > -rc2 already has a fix for it: > > https://lore.kernel.org/linux-mm/20220129021420.PgBIZm-q9%25akpm@xxxxxxxxxxxxxxxxxxxx/ > > Earlier in that function there's a: > > page = compound_head(page); > > So the @page passed to collect_procs() already is a head page. It's wrong though ;-( You set the HWPoison bit on the page after calling compound_head(), so you set the bit on the head page instead of the precise page that had the poison. I'm fixing this up as part of the folio patches, but you may wish to fix it earlier than that.
