• Gerald Schaefer's avatar
    PM / Hibernate / Memory hotplug: Always use for_each_populated_zone() · 98e73dc5
    Gerald Schaefer authored
    Use for_each_populated_zone() instead of for_each_zone() in hibernation
    code. This fixes a bug on s390, where we allow both config options
    HIBERNATION and MEMORY_HOTPLUG, so that we also have a ZONE_MOVABLE
    here. We only allow hibernation if no memory hotplug operation was
    performed, so in fact both features can only be used exclusively, but
    this way we don't need 2 differently configured (distribution) kernels.
    
    If we have an unpopulated ZONE_MOVABLE, we allow hibernation but run
    into a BUG_ON() in memory_bm_test/set/clear_bit() because hibernation
    code iterates through all zones, not only the populated zones, in
    several places. For example, swsusp_free() does for_each_zone() and
    then checks for pfn_valid(), which is true even if the zone is not
    populated, resulting in a BUG_ON() later because the pfn cannot be
    found in the memory bitmap.
    
    Replacing all occurences of for_each_zone() in hibernation code with
    for_each_populated_zone() would fix this issue.
    
    [rjw: Rebased on top of linux-next hibernation patches.]
    Signed-off-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
    Acked-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
    Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
    98e73dc5
snapshot.c 59.1 KB