lkml.org 
[lkml]   [2009]   [Jun]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] [8/16] HWPOISON: Use bitmask/action code for try_to_unmap behaviour
    On Wed, Jun 03, 2009 at 08:46:41PM +0200, Andi Kleen wrote:
    >
    > try_to_unmap currently has multiple modi (migration, munlock, normal unmap)
    > which are selected by magic flag variables. The logic is not very straight
    > forward, because each of these flag change multiple behaviours (e.g.
    > migration turns off aging, not only sets up migration ptes etc.)
    > Also the different flags interact in magic ways.
    >
    > A later patch in this series adds another mode to try_to_unmap, so
    > this becomes quickly unmanageable.
    >
    > Replace the different flags with a action code (migration, munlock, munmap)
    > and some additional flags as modifiers (ignore mlock, ignore aging).
    > This makes the logic more straight forward and allows easier extension
    > to new behaviours. Change all the caller to declare what they want to
    > do.
    >
    > This patch is supposed to be a nop in behaviour. If anyone can prove
    > it is not that would be a bug.
    >
    > Cc: Lee.Schermerhorn@hp.com
    > Cc: npiggin@suse.de
    >
    > Signed-off-by: Andi Kleen <ak@linux.intel.com>
    >
    > ---
    > include/linux/rmap.h | 14 +++++++++++++-
    > mm/migrate.c | 2 +-
    > mm/rmap.c | 40 ++++++++++++++++++++++------------------
    > mm/vmscan.c | 2 +-
    > 4 files changed, 37 insertions(+), 21 deletions(-)
    >
    > Index: linux/include/linux/rmap.h
    > ===================================================================
    > --- linux.orig/include/linux/rmap.h 2009-06-03 19:36:23.000000000 +0200
    > +++ linux/include/linux/rmap.h 2009-06-03 20:39:50.000000000 +0200
    > @@ -84,7 +84,19 @@
    > * Called from mm/vmscan.c to handle paging out
    > */
    > int page_referenced(struct page *, int is_locked, struct mem_cgroup *cnt);
    > -int try_to_unmap(struct page *, int ignore_refs);
    > +
    > +enum ttu_flags {
    > + TTU_UNMAP = 0, /* unmap mode */
    > + TTU_MIGRATION = 1, /* migration mode */
    > + TTU_MUNLOCK = 2, /* munlock mode */
    > + TTU_ACTION_MASK = 0xff,
    > +
    > + TTU_IGNORE_MLOCK = (1 << 8), /* ignore mlock */
    > + TTU_IGNORE_ACCESS = (1 << 9), /* don't age */
    > +};
    > +#define TTU_ACTION(x) ((x) & TTU_ACTION_MASK)

    I still think this is nasty and should work like Gfp flags.



    \
     
     \ /
      Last update: 2009-06-09 11:59    [W:0.022 / U:4.484 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site