• Linus Torvalds's avatar
    mm: get rid of vmacache_flush_all() entirely · 7a9cdebd
    Linus Torvalds authored
    Jann Horn points out that the vmacache_flush_all() function is not only
    potentially expensive, it's buggy too.  It also happens to be entirely
    unnecessary, because the sequence number overflow case can be avoided by
    simply making the sequence number be 64-bit.  That doesn't even grow the
    data structures in question, because the other adjacent fields are
    already 64-bit.
    So simplify the whole thing by just making the sequence number overflow
    case go away entirely, which gets rid of all the complications and makes
    the code faster too.  Win-win.
    [ Oleg Nesterov points out that the VMACACHE_FULL_FLUSHES statistics
      also just goes away entirely with this ]
    Reported-by: default avatarJann Horn <jannh@google.com>
    Suggested-by: default avatarWill Deacon <will.deacon@arm.com>
    Acked-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: stable@kernel.org
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
mm_types.h 19.5 KB