> I suspect for the swap->zram we should always get charged pages, because > we're effectively writing out charged anon/shmem pages only -- without > any buffer in between. Hi David，the charged memory will be released in swap->zram. New pages are allocated by alloc_zspage(), and we did not charge the page directly，but the objects(like slab), because the zspage are shared by any memcg. > > For the fs->zram or direct zram access device case I'm not so sure. It > highly depends on what gets mapped into the bio (e.g., a kernel buffer, > zeropage, ...). If it's a pagecache page, that should be charged and > we're good. No so sure about fs metadata or some other fs cases (e.g., > write() to a file that bypass the pagecache). > Yes， the pagecaches are charged in fs->zram, but will be released if we drop the cache. the compressed objects are not charged. > -- > Cheers, > > David / dhildenb >
