On Tue, May 12, 2026 at 11:58:27AM -0400, Michael S. Tsirkin wrote: > On Tue, May 12, 2026 at 11:56:02AM -0400, Gregory Price wrote: > > On Mon, May 11, 2026 at 05:03:35AM -0400, Michael S. Tsirkin wrote: > > > When two buddy pages merge in __free_one_page(), preserve > > > PG_zeroed on the merged page only if both buddies have the > > > flag set. Otherwise clear it. > > > > > > The merged page would inherit PG_zeroed, and a later __GFP_ZERO > > > allocation would skip zeroing stale data in the non-zero half. > > > > > > Signed-off-by: Michael S. Tsirkin <[email protected]> > > > Assisted-by: Claude:claude-opus-4-6 > > > Assisted-by: cursor-agent:GPT-5.4-xhigh > > > --- > > > mm/page_alloc.c | 15 ++++++++++++++- > > > 1 file changed, 14 insertions(+), 1 deletion(-) > > > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > > index bd3b909cacdf..d70c9ba6b329 100644 > > > --- a/mm/page_alloc.c > > > +++ b/mm/page_alloc.c > > > @@ -940,10 +940,14 @@ static inline void __free_one_page(struct page > > > *page, > > > unsigned long buddy_pfn = 0; > > > unsigned long combined_pfn; > > > struct page *buddy; > > > + bool buddy_zeroed; > > > + bool page_zeroed; > > > > If you want to play some code golf, i think you can get away with a > > single bool here: > > > > bool zeroed; > > zeroed = PageZeroed(buddy); > > zeroed &= PageZeroed(page); > > > > if (zeroed) > > __SetPageZeroed(page); > > > > ~Gregory > > Does it matter? It makes my head hurt. >
Less code generally means less bugs, but this is more style nits than anything. Either way Reviewed-by: Gregory Price <[email protected]> ~Gregory
