On Thu, Aug 21, 2025 at 02:55:34PM -0700, Boris Burkov wrote: > I would like to revisit Qu's proposal to not charge btrfs extent_buffer > allocations to the user's cgroup. > > https://lore.kernel.org/linux-mm/b5fef5372ae454a7b6da4f2f75c427aeab6a07d6.1727498749.git.wqu@xxxxxxxx/ > > I believe it is detrimental to account these global pages to the cgroup > using them, basically at random. A bit more justification and explanation > in the patches themselves. > > --- > Changelog: > v4: > - change the concept from "uncharged" to "kernel_file" > - no longer violates the invariant that each mapped folio has a memcg > when CONFIG_MEMCG=y > - no longer really tied to memcg conceptually, so simplify build/helpers > v3: > - use mod_node_page_state since we will never count cgroup stats > - include Shakeel's patch that removes a WARNING triggered by this series > v2: > - switch from filemap_add_folio_nocharge() to AS_UNCHARGED on the > address_space. > - fix an interrupt safety bug in the vmstat patch. > - fix some foolish build errors for CONFIG_MEMCG=n > > > > Boris Burkov (3): > mm/filemap: add AS_KERNEL_FILE > mm: add vmstat for kernel_file pages > btrfs: set AS_KERNEL_FILE on the btree_inode > > fs/btrfs/disk-io.c | 1 + > include/linux/mmzone.h | 1 + > include/linux/pagemap.h | 2 ++ > mm/filemap.c | 13 +++++++++++++ > mm/vmstat.c | 1 + For the btrfs parts, Acked-by: David Sterba <dsterba@xxxxxxxx>
