Hello, The way configuration and statistics are handled in block cgroup is rather depressing. Every configuration and stat counter are defined in blkcg core and specific policy implementations should go through some blkcg interface to access and manipulate them and be notified of the changes. By doing things this way, it achieves both complexity and inflexibility - the code paths are unnecessarily complex while not achieving any layering or modularity. A configuration or statistics counter cannot be added to policies without modifying multiple places in blkcg core code. Wanna implement a new policy? Good luck. The implementation details are sad too. Stuff goes through needless layers of functions with hard coded cases on specific counters and configurations and fields specific to policies are thrown into common area with some shared and others unused. This patchset is an attempt at bringing some sanity to blkcg config and stat file handling. It makes use of the pending dynamic cgroup file type addition / removal support [1], which will be merged into cgroup/for-3.5 once 3.4-rc1 is released. All conf and stat file handling is moved into the policy implementaiton the files belong to and blkcg supplies helpers to ease file handling in policy implementations without requiring full knowledge of all configurations and statistic counters. This patchset sheds >500 lines of code while maintaining the same features and with more comments and much more modular design. Yeah, it was just wrong. This patchset contains the following 21 patches 0001-blkcg-remove-unused-pol-and-plid-parameters.patch 0002-blkcg-BLKIO_STAT_CPU_SECTORS-doesn-t-have-subcounter.patch 0003-blkcg-introduce-blkg_stat-and-blkg_rwstat.patch 0004-blkcg-restructure-statistics-printing.patch 0005-blkcg-drop-blkiocg_file_write_u64.patch 0006-blkcg-restructure-configuration-printing.patch 0007-blkcg-restructure-blkio_group-configruation-setting.patch 0008-blkcg-blkg_conf_prep.patch 0009-blkcg-export-conf-stat-helpers-to-prepare-for-reorga.patch 0010-blkcg-implement-blkio_policy_type-cftypes.patch 0011-blkcg-move-conf-stat-file-handling-code-to-policies.patch 0012-cfq-collapse-cfq.h-into-cfq-iosched.c.patch 0013-blkcg-move-statistics-update-code-to-policies.patch 0014-blkcg-cfq-doesn-t-need-per-cpu-dispatch-stats.patch 0015-blkcg-add-blkio_policy_ops-operations-for-exit-and-s.patch 0016-blkcg-move-blkio_group_stats-to-cfq-iosched.c.patch 0017-blkcg-move-blkio_group_stats_cpu-and-friends-to-blk-.patch 0018-blkcg-move-blkio_group_conf-weight-to-cfq.patch 0019-blkcg-move-blkio_group_conf-iops-and-bps-to-blk-thro.patch 0020-blkcg-pass-around-pd-pdata-instead-of-pd-itself-in-p.patch 0021-blkcg-drop-BLKCG_STAT_-PRIV-POL-OFF-macros.patch and is on top of block/for-3.5/core eb7d8c07f9 "cfq: fix cfqg ref handling..." + [1] cgroup-cftypes d954ca6469 "cgroup: implement cgroup_rm_cftypes()" Note that the cgroup branch is temporary and the merge between the two branches aren't trivial. I'll prepare a proper merged branch once the cgroup/for-3.5 branch is settled. This patchset is also available in the following git branch. git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git blkcg-files diffstat follows. block/blk-cgroup.c | 1343 ++++++--------------------------------------------- block/blk-cgroup.h | 414 ++++++--------- block/blk-throttle.c | 318 ++++++++++-- block/cfq-iosched.c | 567 +++++++++++++++++++-- block/cfq.h | 118 ---- 5 files changed, 1102 insertions(+), 1658 deletions(-) -- tejun [1] http://thread.gmane.org/gmane.linux.kernel.containers/22623 _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
