On 3/6/24 19:24, Suren Baghdasaryan wrote: > When a non-compound multi-order page is freed, it is possible that a > speculative reference keeps the page pinned. In this case we free all > pages except for the first page, which will be freed later by the last > put_page(). However put_page() ignores the order of the page being freed, > treating it as a 0-order page. This creates a memory accounting imbalance > because the pages freed in __free_pages() do not have their own alloc_tag > and their memory was accounted to the first page. To fix this the first > page should adjust its allocation size counter when "tail" pages are freed. > > Reported-by: Vlastimil Babka <vbabka@xxxxxxx> > Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
