[PATCH v2 0/2] cgroup: Sync cgroup id and inode number

[Namhyung Kim]

Hello,

This patchset changes cgroup inode number and id management to be in
sync with kernfs.  The cgroup inode number is managed by kernfs but
cgroup id is allocated by a separate idr.  The idea is to have a
single id for internal usage, inode number and file handle which can
be accessed from userspace.  Actually this work is from Tejun who also
provided the idea.  I just took over the work and fixed some errors
and finally was able to run perf for testing.

The background of this work is that I want to add cgroup sampling
feature in the perf event subsystem.  As Tejun mentioned that using
cgroup id is not enough and it'd better using file handle instead.
But getting file handle in perf NMI handler is not possible so I want
to get the info from a cgroup node.

The first patch converted kernfs id into a single 64bit number and in
the second patch cgroup uses the kernfs id as cgroup id.

The patches are based on the for-next branch in Tejun's cgroup tree.
Tested with tools/testing/selftests/cgroup/test_stress.sh.

Thanks
Namhyung


Tejun Heo (2):
      kernfs: Convert to u64 id
      cgroup: Use 64bit id from kernfs

 fs/kernfs/dir.c                  | 36 +++++++++++++++++++------------
 fs/kernfs/file.c                 |  4 ++--
 fs/kernfs/inode.c                |  4 ++--
 fs/kernfs/kernfs-internal.h      |  2 --
 fs/kernfs/mount.c                | 92 +++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------
 include/linux/cgroup-defs.h      | 18 ++++------------
 include/linux/cgroup.h           | 17 +++++++--------
 include/linux/exportfs.h         |  5 +++++
 include/linux/kernfs.h           | 47 +++++++++++++++++++++++++----------------
 include/net/netprio_cgroup.h     |  8 +++----
 include/trace/events/writeback.h | 92 ++++++++++++++++++++++++++++++++++++++++----------------------------------------
 kernel/bpf/helpers.c             |  2 +-
 kernel/cgroup/cgroup.c           | 68 +++++++++++++++++++----------------------------------------
 kernel/trace/blktrace.c          | 66 +++++++++++++++++++++++++++------------------------------
 net/core/filter.c                |  4 ++--
 net/core/netprio_cgroup.c        |  4 ++--
 16 files changed, 236 insertions(+), 233 deletions(-)

-- 
2.23.0.700.g56cf767bdb-goog