• Balbir Singh's avatar
    cgroups: add an owner to the mm_struct · cf475ad2
    Balbir Singh authored
    Remove the mem_cgroup member from mm_struct and instead adds an owner.
    
    This approach was suggested by Paul Menage.  The advantage of this approach
    is that, once the mm->owner is known, using the subsystem id, the cgroup
    can be determined.  It also allows several control groups that are
    virtually grouped by mm_struct, to exist independent of the memory
    controller i.e., without adding mem_cgroup's for each controller, to
    mm_struct.
    
    A new config option CONFIG_MM_OWNER is added and the memory resource
    controller selects this config option.
    
    This patch also adds cgroup callbacks to notify subsystems when mm->owner
    changes.  The mm_cgroup_changed callback is called with the task_lock() of
    the new task held and is called just prior to changing the mm->owner.
    
    I am indebted to Paul Menage for the several reviews of this patchset and
    helping me make it lighter and simpler.
    
    This patch was tested on a powerpc box, it was compiled with both the
    MM_OWNER config turned on and off.
    
    After the thread group leader exits, it's moved to init_css_state by
    cgroup_exit(), thus all future charges from runnings threads would be
    redirected to the init_css_set's subsystem.
    Signed-off-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
    Cc: Pavel Emelianov <xemul@openvz.org>
    Cc: Hugh Dickins <hugh@veritas.com>
    Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
    Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
    Cc: Hirokazu Takahashi <taka@valinux.co.jp>
    Cc: David Rientjes <rientjes@google.com>,
    Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
    Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
    Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
    Reviewed-by: default avatarPaul Menage <menage@google.com>
    Cc: Oleg Nesterov <oleg@tv-sign.ru>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    cf475ad2
exit.c 43 KB