[PATCHSET block/for-4.3] writeback: cgroup writeback updates

[Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

Hello,

This patchset contains the following updates to cgroup writeback
support

* bdi_writeback iteration fix which could lead to some wb's being
  skipped or repeated during e.g. sync under memory pressure.

* Simplification of wb work wait mechanism.

* Writeback tracepoints updated to report cgroup.

and is consisted of the following five patches.

 0001-writeback-bdi_for_each_wb-iteration-is-memcg-ID-base.patch
 0002-writeback-remove-wb_writeback_work-single_wait-done.patch
 0003-writeback-explain-why-inode-is-allowed-to-be-NULL-fo.patch
 0004-kernfs-implement-kernfs_path_len.patch
 0005-writeback-update-writeback-tracepoints-to-report-cgr.patch

The patchset is on top of d770e558e219 ("Linux 4.2-rc1") and available
in the following git branch.

 git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-cgroup-writeback-updates-for-4.3

diffstat follows.  Thanks.

 fs/fs-writeback.c                |  139 +++++++++---------------------
 fs/kernfs/dir.c                  |   23 ++++
 include/linux/backing-dev.h      |   24 ++---
 include/linux/kernfs.h           |    4 
 include/trace/events/writeback.h |  180 ++++++++++++++++++++++++++++++---------
 mm/page-writeback.c              |    6 -
 6 files changed, 226 insertions(+), 150 deletions(-)

--
tejun