• Kirill A. Shutemov's avatar
    mm: nominate faultaround area in bytes rather than page order · a9b0f861
    Kirill A. Shutemov authored
    There is evidencs that the faultaround feature is less relevant on
    architectures with page size bigger then 4k.  Which makes sense since page
    fault overhead per byte of mapped area should be less there.
    
    Let's rework the feature to specify faultaround area in bytes instead of
    page order.  It's 64 kilobytes for now.
    
    The patch effectively disables faultaround on architectures with page size
    >= 64k (like ppc64).
    
    It's possible that some other size of faultaround area is relevant for a
    platform.  We can expose `fault_around_bytes' variable to arch-specific
    code once such platforms will be found.
    Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
    Cc: Rusty Russell <rusty@rustcorp.com.au>
    Cc: Hugh Dickins <hughd@google.com>
    Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Rik van Riel <riel@redhat.com>
    Cc: Mel Gorman <mgorman@suse.de>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Ingo Molnar <mingo@kernel.org>
    Cc: Dave Hansen <dave.hansen@intel.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    a9b0f861
memory.c 100 KB