lkml.org 
[lkml]   [2007]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: Regression in 2.6.23-rc2-mm2, mounting cpusets causes a hang
    From
    Date
    On Mon, 2007-08-13 at 15:12 -0500, Serge E. Hallyn wrote:
    > Quoting Dhaval Giani (dhaval@linux.vnet.ibm.com):
    > > Hi,
    > >
    > > On mounting cpusets using containers, I have been hitting the following
    > > bug.
    > >
    > >
    > > -----------[ cut here ]------------
    > > kernel BUG at kernel/cpuset.c:331!
    <snip>
    > > CONFIG_HIGHMEM=y
    > > CONFIG_X86_PAE=y
    > > # CONFIG_NUMA is not set
    > > CONFIG_ARCH_POPULATES_NODE_MAP=y
    > > CONFIG_SELECT_MEMORY_MODEL=y
    > > CONFIG_FLATMEM_MANUAL=y
    > > # CONFIG_DISCONTIGMEM_MANUAL is not set
    > > # CONFIG_SPARSEMEM_MANUAL is not set
    > > CONFIG_FLATMEM=y
    > > CONFIG_FLAT_NODE_MEM_MAP=y
    > > # CONFIG_SPARSEMEM_STATIC is not set
    > > CONFIG_SPLIT_PTLOCK_CPUS=4
    > > CONFIG_RESOURCES_64BIT=y
    > > CONFIG_ZONE_DMA_FLAG=1
    <snip>
    >
    > Yeah, I'm seeing the same thing. Oddly, my node_states[N_NORMAL_MEMORY]
    > and node_states[N_HIGH_MEMORY] are empty, while node_states[N_ONLINE]
    > contains my single cpu (on i386 kvm image).
    >
    > -serge

    Yes, you'll definitely hit that BUG if the N_HIGH_MEMORY mask is empty.
    So far, I can't see how this could be, tho'. __build_all_zonelists()
    should be called for non-NUMA as well as NUMA. It iterates over "all
    on-line nodes"--the N_ONLINE state, which is initialized to have node 0
    on-line. That should work for a non-NUMA i386, right?

    In the loop over all on-line nodes, __build_all_zonelists() sets
    N_HIGH_MEMORY for each [on-line] node with ANY present pages--i.e.,
    non-zero pgdat->node_present_pages. Then, check_for_regular_memory()
    will set N_NORMAL_MEMORY for any nodes with non-zero zone->present_pages
    for any zone <= ZONE_NORMAL.

    I don't have an i386 test system to verify this, but from cscope, it
    looks like the pgdat, including node_present_pages should be setup in
    the following call path:

    start_kernel()->setup_arch()->zone_sizes_init()->
    free_area_init_zones()->free_area_init_zone->
    calculate_node_total_pages()

    This is called before build_all_zonelists()--also from start_kernel(),
    so node_present_pages should be non-zero when we populate the N_*_MEMORY
    states...

    Any ideas, anyone?

    Lee




    -
    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: 2007-08-14 18:35    [W:0.058 / U:1.500 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site