• Paul Gortmaker's avatar
    mm: audit/fix non-modular users of module_init in core code · a64fb3cd
    Paul Gortmaker authored
    Code that is obj-y (always built-in) or dependent on a bool Kconfig
    (built-in or absent) can never be modular.  So using module_init as an
    alias for __initcall can be somewhat misleading.
    
    Fix these up now, so that we can relocate module_init from init.h into
    module.h in the future.  If we don't do this, we'd have to add module.h
    to obviously non-modular code, and that would be a worse thing.
    
    The audit targets the following module_init users for change:
     mm/ksm.c                       bool KSM
     mm/mmap.c                      bool MMU
     mm/huge_memory.c               bool TRANSPARENT_HUGEPAGE
     mm/mmu_notifier.c              bool MMU_NOTIFIER
    
    Note that direct use of __initcall is discouraged, vs.  one of the
    priority categorized subgroups.  As __initcall gets mapped onto
    device_initcall, our use of subsys_initcall (which makes sense for these
    files) will thus change this registration from level 6-device to level
    4-subsys (i.e.  slightly earlier).
    
    However no observable impact of that difference has been observed during
    testing.
    
    One might think that core_initcall (l2) or postcore_initcall (l3) would
    be more appropriate for anything in mm/ but if we look at some actual
    init functions themselves, we see things like:
    
    mm/huge_memory.c --> hugepage_init     --> hugepage_init_sysfs
    mm/mmap.c        --> init_user_reserve --> sysctl_user_reserve_kbytes
    mm/ksm.c         --> ksm_init          --> sysfs_create_group
    
    and hence the choice of subsys_initcall (l4) seems reasonable, and at
    the same time minimizes the risk of changing the priority too
    drastically all at once.  We can adjust further in the future.
    
    Also, several instances of missing ";" at EOL are fixed.
    Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    a64fb3cd
huge_memory.c 77.8 KB