On 2026-07-01 at 19:05 +1000, Li Zhe <[email protected]> wrote... > The comment in __init_zone_device_page() still uses the old > MEMORY_TYPE_* names and implies that FS_DAX pages regain a > refcount of 1 in the free path. That no longer matches the code. > > Update the comment to describe the current policy correctly: > MEMORY_DEVICE_GENERIC pages regain a refcount of 1 in the free path, > while the remaining ZONE_DEVICE types start from 0 here and raise the > count again when the allocator or driver hands the page out. > > No functional change intended. > > Signed-off-by: Li Zhe <[email protected]>
Accidentally just sent my response on v4, but this looks correct to me: Reviewed-by: Alistair Popple <[email protected]> > --- > mm/mm_init.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/mm/mm_init.c b/mm/mm_init.c > index 0f64909e8d20..95808ab5cfdb 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -1030,13 +1030,9 @@ static void __ref __init_zone_device_page(struct page > *page, unsigned long pfn, > page->zone_device_data = NULL; > > /* > - * ZONE_DEVICE pages other than MEMORY_TYPE_GENERIC are released > - * directly to the driver page allocator which will set the page count > - * to 1 when allocating the page. > - * > - * MEMORY_TYPE_GENERIC and MEMORY_TYPE_FS_DAX pages automatically have > - * their refcount reset to one whenever they are freed (ie. after > - * their refcount drops to 0). > + * MEMORY_DEVICE_GENERIC pages regain a refcount of 1 in the free > + * path. The remaining ZONE_DEVICE types start from 0 here and raise > + * the count again when the allocator or driver hands the page out. > */ > switch (pgmap->type) { > case MEMORY_DEVICE_FS_DAX: > -- > 2.20.1
