On Tue, Jan 04, 2022 at 01:10:37AM +0100, Vlastimil Babka wrote: > page->memcg_data is used with MEMCG_DATA_OBJCGS flag only for slab pages > so convert all the related infrastructure to struct slab. Also use > struct folio instead of struct page when resolving object pointers. > > This is not just mechanistic changing of types and names. Now in > mem_cgroup_from_obj() we use folio_test_slab() to decide if we interpret > the folio as a real slab instead of a large kmalloc, instead of relying > on MEMCG_DATA_OBJCGS bit that used to be checked in page_objcgs_check(). > Similarly in memcg_slab_free_hook() where we can encounter > kmalloc_large() pages (here the folio slab flag check is implied by > virt_to_slab()). As a result, page_objcgs_check() can be dropped instead > of converted. Btw, it seems that with some minimal changes we can drop the whole thing with the changing of the lower bit and rely on the slab page flag. I'll prepare a patch on top of your series. Thanks!
