• Mel Gorman's avatar
    mm: numa: Create basic numa page hinting infrastructure · d10e63f2
    Mel Gorman authored
    Note: This patch started as "mm/mpol: Create special PROT_NONE
    	infrastructure" and preserves the basic idea but steals *very*
    	heavily from "autonuma: numa hinting page faults entry points" for
    	the actual fault handlers without the migration parts.	The end
    	result is barely recognisable as either patch so all Signed-off
    	and Reviewed-bys are dropped. If Peter, Ingo and Andrea are ok with
    	this version, I will re-add the signed-offs-by to reflect the history.
    
    In order to facilitate a lazy -- fault driven -- migration of pages, create
    a special transient PAGE_NUMA variant, we can then use the 'spurious'
    protection faults to drive our migrations from.
    
    The meaning of PAGE_NUMA depends on the architecture but on x86 it is
    effectively PROT_NONE. Actual PROT_NONE mappings will not generate these
    NUMA faults for the reason that the page fault code checks the permission on
    the VMA (and will throw a segmentation fault on actual PROT_NONE mappings),
    before it ever calls handle_mm_fault.
    
    [dhillf@gmail.com: Fix typo]
    Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
    Reviewed-by: default avatarRik van Riel <riel@redhat.com>
    d10e63f2
memory.c 112 KB