lkml.org 
[lkml]   [2007]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: The performance and behaviour of the anti-fragmentation related patches
    On Fri, 2 Mar 2007, Andrew Morton wrote:

    > > Linux is *not* happy on 256GB systems. Even on some 32GB systems
    > > the swappiness setting *needs* to be tweaked before Linux will even
    > > run in a reasonable way.
    >
    > Please send testcases.

    It is not happy if you put 256GB into one zone. We are fine with 1k nodes
    with 8GB each and a 16k page size (which reduces the number of
    page_structs to manage by a fourth). So the total memory is 8TB which is
    significantly larger than 256GB.

    If we do this node/zone merging and reassign MAX_ORDER blocks to virtual
    node/zones for containers (with their own LRU etc) then this would also
    reduce the number of page_structs on the list and may make things a bit
    easier.

    We would then produce the same effect as the partitioning via NUMA nodes
    on our 8TB boxes. However, then you still have a bandwidth issue since
    your 256 likely only has a single bus and all memory traffic for the
    node/zones has to go through this single bottleneck. That bottleneck does
    not exist on NUMA machines.


    -
    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: 2007-03-02 18:27    [W:4.612 / U:0.116 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site