• Petr Tesarik's avatar
    kexec: save PG_head_mask in VMCOREINFO · b3acc56b
    Petr Tesarik authored
    To allow filtering of huge pages, makedumpfile must be able to identify
    them in the dump.  This can be done by checking the appropriate page
    flag, so communicate its value to makedumpfile through the VMCOREINFO
    interface.
    
    There's only one small catch.  Depending on how many page flags are
    available on a given architecture, this bit can be called PG_head or
    PG_compound.
    
    I sent a similar patch back in 2012, but Eric Biederman did not like
    using an #ifdef.  So, this time I'm adding a common symbol
    (PG_head_mask) instead.
    
    See https://lkml.org/lkml/2012/11/28/91 for the previous version.
    Signed-off-by: default avatarPetr Tesarik <ptesarik@suse.cz>
    Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
    Cc: Eric Biederman <ebiederm@xmission.com>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Fengguang Wu <fengguang.wu@intel.com>
    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Cc: Shaohua Li <shli@kernel.org>
    Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
    Cc: Sasha Levin <sasha.levin@oracle.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    b3acc56b
kexec.c 42.7 KB