• Tejun Heo's avatar
    blkcg: rename subsystem name from blkio to io · c165b3e3
    Tejun Heo authored
    
    
    blkio interface has become messy over time and is currently the
    largest.  In addition to the inconsistent naming scheme, it has
    multiple stat files which report more or less the same thing, a number
    of debug stat files which expose internal details which shouldn't have
    been part of the public interface in the first place, recursive and
    non-recursive stats and leaf and non-leaf knobs.
    
    Both recursive vs. non-recursive and leaf vs. non-leaf distinctions
    don't make any sense on the unified hierarchy as only leaf cgroups can
    contain processes.  cgroups is going through a major interface
    revision with the unified hierarchy involving significant fundamental
    usage changes and given that a significant portion of the interface
    doesn't make sense anymore, it's a good time to reorganize the
    interface.
    
    As the first step, this patch renames the external visible subsystem
    name from "blkio" to "io".  This is more concise, matches the other
    two major subsystem names, "cpu" and "memory", and better suited as
    blkcg will be involved in anything writeback related too whether an
    actual block device is involved or not.
    
    As the subsystem legacy_name is set to "blkio", the only userland
    visible change outside the unified hierarchy is that blkcg is reported
    as "io" instead of "blkio" in the subsystem initialized message during
    boot.  On the unified hierarchy, blkcg now appears as "io".
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Cc: Li Zefan <lizefan@huawei.com>
    Cc: Johannes Weiner <hannes@cmpxchg.org>
    Cc: cgroups@vger.kernel.org
    Signed-off-by: default avatarJens Axboe <axboe@fb.com>
    c165b3e3
blk-cgroup.h 21.8 KB