• Michal Hocko's avatar
    mm, memory_hotplug: get rid of is_zone_device_section · 1b862aec
    Michal Hocko authored
    Device memory hotplug hooks into regular memory hotplug only half way.
    It needs memory sections to track struct pages but there is no
    need/desire to associate those sections with memory blocks and export
    them to the userspace via sysfs because they cannot be onlined anyway.
    
    This is currently expressed by for_device argument to arch_add_memory
    which then makes sure to associate the given memory range with
    ZONE_DEVICE.  register_new_memory then relies on is_zone_device_section
    to distinguish special memory hotplug from the regular one.  While this
    works now, later patches in this series want to move __add_zone outside
    of arch_add_memory path so we have to come up with something else.
    
    Add want_memblock down the __add_pages path and use it to control
    whether the section->memblock association should be done.
    arch_add_memory then just trivially want memblock for everything but
    for_device hotplug.
    
    remove_memory_section doesn't need is_zone_device_section either.  We
    can simply skip all the memblock specific cleanup if there is no
    memblock for the given section.
    
    This shouldn't introduce any functional change.
    
    Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.orgSigned-off-by: default avatarMichal Hocko <mhocko@suse.com>
    Tested-by: default avatarDan Williams <dan.j.williams@intel.com>
    Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: Andrea Arcangeli <aarcange@redhat.com>
    Cc: Balbir Singh <bsingharora@gmail.com>
    Cc: Daniel Kiper <daniel.kiper@oracle.com>
    Cc: David Rientjes <rientjes@google.com>
    Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
    Cc: Igor Mammedov <imammedo@redhat.com>
    Cc: Jerome Glisse <jglisse@redhat.com>
    Cc: Joonsoo Kim <js1304@gmail.com>
    Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
    Cc: Mel Gorman <mgorman@suse.de>
    Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
    Cc: Tobias Regnery <tobias.regnery@gmail.com>
    Cc: Toshi Kani <toshi.kani@hpe.com>
    Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
    Cc: Xishi Qiu <qiuxishi@huawei.com>
    Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    1b862aec
init.c 5.72 KB