lkml.org 
[lkml]   [2006]   [Dec]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] Add __GFP_MOVABLE for callers to flag allocations that may be migrated
    On Mon, 4 Dec 2006 20:34:29 +0000 (GMT)
    Mel Gorman <mel@csn.ul.ie> wrote:

    > > IOW: big-picture where-do-we-go-from-here stuff.
    > >
    >
    > Start with lumpy reclaim,

    I had lumpy-reclaim in my todo-queue but it seems to have gone away. I
    think I need a lumpy-reclaim resend, please.

    > then I'd like to merge page clustering piece by
    > piece, ideally with one of the people with e1000 problems testing to see
    > does it make a difference.
    >
    > Assuming they are shown to help, where we'd go from there would be stuff
    > like;
    >
    > 1. Keep non-movable and reapable allocations at the lower PFNs as much as
    > possible. This is so DIMMS for higher PFNs can be removed (doesn't
    > exist)

    "as much as possible" won't suffice, I suspect. If there's any chance at
    all that a non-moveable page can land in a hot-unpluggable region then
    there will be failure scenarios. Easy-to-hit ones, I suspect.

    > 2. Use page migration to compact memory rather than depending solely on
    > reclaim (doesn't exist)

    Yup.

    > 3. Introduce a mechanism for marking a group of pages as being offlined so
    > that they are not reallocated (code that does something like this
    > exists)

    yup.

    > 4. Resurrect the hotplug-remove code (exists, but probably very stale)

    I don't even remember what that looks like.

    > 5. Allow allocations for hugepages outside of the pool as long as the
    > process remains with it's locked_vm limits (patches were posted to
    > libhugetlbfs last Friday. will post to linux-mm tomorrow).

    hm.


    I'm not saying that we need to do memory hot-unplug immediately. But the
    overlaps between this and anti-frag and lumpiness are sufficient that I do
    think that we need to work out how we'll implement hot-unplug, so we don't
    screw ourselves up later on.

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-12-04 23:39    [W:2.878 / U:0.140 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site