Hello, This patchset contains only the block part of the following [1] [PATCHSET v2 btrfs/for-next] blkcg, btrfs: fix cgroup writeback support with the following changes * wbc_account_io() is renamed to wbc_account_cgroup_owner() and wbc->no_account_io to wbc->no_cgroup_owner for clarity. When writeback is executed asynchronously (e.g. for compression), bios are bounced to and issued by worker pool shared by all cgroups. This leads to significant priority inversions when cgroup IO control is in use - IOs for a low priority cgroup can tie down the workers forcing higher priority IOs to wait behind them. This patchset adds an bio punt mechanism to blkcg and updates btrfs to issue async IOs through it. A bio tagged with REQ_CGROUP_PUNT flag is bounced to the asynchronous issue context of the associated blkcg on bio_submit(). As the bios are issued from per-blkcg work items, there's no concern for priority inversions and it doesn't require invasive changes to the filesystems. The mechanism should be generally useful for IO control support across different filesystems. This patchset contains the following 5 patches. 0001-cgroup-blkcg-Prepare-some-symbols-for-module-and-CON.patch 0002-blkcg-writeback-Rename-wbc_account_io-to-wbc_account.patch 0003-blkcg-writeback-Add-wbc-no_cgroup_owner.patch 0004-blkcg-writeback-Implement-wbc_blkcg_css.patch 0005-blkcg-implement-REQ_CGROUP_PUNT.patch The patches are also available in the following branch. git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-blkcg-punt Thanks, diffstat follows. Documentation/admin-guide/cgroup-v2.rst | 2 - block/blk-cgroup.c | 54 ++++++++++++++++++++++++++++++++ block/blk-core.c | 3 + fs/btrfs/extent_io.c | 4 +- fs/buffer.c | 2 - fs/ext4/page-io.c | 2 - fs/f2fs/data.c | 4 +- fs/fs-writeback.c | 13 ++++--- fs/mpage.c | 2 - include/linux/backing-dev.h | 1 include/linux/blk-cgroup.h | 16 ++++++++- include/linux/blk_types.h | 10 +++++ include/linux/cgroup.h | 1 include/linux/writeback.h | 41 ++++++++++++++++++++---- 14 files changed, 134 insertions(+), 21 deletions(-) -- tejun [1] http://lkml.kernel.org/r/20190615182453.843275-1-tj@xxxxxxxxxx
