• KAMEZAWA Hiroyuki's avatar
    memcg: fix page_cgroup allocation · 94b6da5a
    KAMEZAWA Hiroyuki authored
    page_cgroup_init() is called from mem_cgroup_init(). But at this
    point, we cannot call alloc_bootmem().
    (and this caused panic at boot.)
    
    This patch moves page_cgroup_init() to init/main.c.
    
    Time table is following:
    ==
      parse_args(). # we can trust mem_cgroup_subsys.disabled bit after this.
      ....
      cgroup_init_early()  # "early" init of cgroup.
      ....
      setup_arch()         # memmap is allocated.
      ...
      page_cgroup_init();
      mem_init();   # we cannot call alloc_bootmem after this.
      ....
      cgroup_init() # mem_cgroup is initialized.
    ==
    
    Before page_cgroup_init(), mem_map must be initialized. So,
    I added page_cgroup_init() to init/main.c directly.
    
    (*) maybe this is not very clean but
        - cgroup_init_early() is too early
        - in cgroup_init(), we have to use vmalloc instead of alloc_bootmem().
        use of vmalloc area in x86-32 is important and we should avoid very large
        vmalloc() in x86-32. So, we want to use alloc_bootmem() and added page_cgroup_init()
        directly to init/main.c
    
    [akpm@linux-foundation.org: remove unneeded/bad mem_cgroup_subsys declaration]
    [akpm@linux-foundation.org: fix build]
    Acked-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
    Tested-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
    Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    94b6da5a
memcontrol.c 28.6 KB