On 4/21/26 04:38, Gregory Price wrote: > On Mon, Apr 20, 2026 at 07:33:38PM -0400, Michael S. Tsirkin wrote: >> On Mon, Apr 20, 2026 at 08:20:57PM +0200, David Hildenbrand (Arm) wrote: >> >>> >>> Which would *already* be the case of you use folio_alloc(GFP_ZERO) >>> instead of magical vma_alloc_folio() + folio_zero_user(). >>> >>> I don't really see how vma_alloc_folio_hints() -- that also consumes the >>> address -- is any better in that regard? >> >> By itself, it is not. But the issue is propagating the address from >> there all over mm. If we miss even one place - we get a subtle cache >> corruption on non x86. >> > > Why does it need to propogate? > > Can we leave folio_zero_user() callers the same, but add a PG_zeroed > check in folio_zero_user() that skips the zeroing (but not the cache > flush) and clear the PG_zeroed bit?
folio_zero_user() is just an abomination, really. -- Cheers, David
