On 6/8/26 16:08, Michael S. Tsirkin wrote: > On Mon, Jun 08, 2026 at 02:46:34PM +0200, David Hildenbrand (Arm) wrote: >> On 6/8/26 14:25, Lorenzo Stoakes wrote: >>> >>> Do not put comments about specific expected races like this in the commit >>> message but not in the code. Subtleties need to be called out. >>> >>> The commit message also doesn't at all explain why PG_zeroed doesn't >>> suffice here. >>> >>> >>> I really don't understand why you have a 'zeroed' folio flag but need to >>> also have new API calls to detect that? >>> >>> They're also HORRIBLY named. Zeroed as in what? Zero page? Huge zero page? >>> Memory zeroed by kernel? Pages that userland happen to have zeroed? Or host >>> VM zeroed? >>> >>> Each are cases we address individually and relate to folios. >>> >>> You absolutely fail to clarify _which one_ you mean, and provide absolutely >>> no documentation and add an exported mm API with no description. >>> >>> This is just I think not something we want to add? Especially on something >>> so fundamental? >> >> I raised previously that providing a folio helper is odd, and that I >> suggested >> that we defer this change. > > Sadly it's a dependency actually - without it memcg failures would cause > repeated re-zeroing where previously it failed without zeroing.
Oh, you mean that we succeeded allocating (+zeroing) but failed to charge? I don't immediately see that to be a real problem? -- Cheers, David
