lkml.org 
[lkml]   [2009]   [Nov]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [BUGFIX][PATCH] oom-kill: fix NUMA consraint check with nodemask v3
    Date
    > On Wed, 11 Nov 2009, KOSAKI Motohiro wrote:
    >
    > > > > {
    > > > > -#ifdef CONFIG_NUMA
    > > > > struct zone *zone;
    > > > > struct zoneref *z;
    > > > > enum zone_type high_zoneidx = gfp_zone(gfp_mask);
    > > > > - nodemask_t nodes = node_states[N_HIGH_MEMORY];
    > > > > + int ret = CONSTRAINT_NONE;
    > > > >
    > > > > - for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
    > > > > - if (cpuset_zone_allowed_softwall(zone, gfp_mask))
    > > > > - node_clear(zone_to_nid(zone), nodes);
    > > > > - else
    > > > > + /*
    > > > > + * The nodemask here is a nodemask passed to alloc_pages(). Now,
    > > > > + * cpuset doesn't use this nodemask for its hardwall/softwall/hierarchy
    > > > > + * feature. mempolicy is an only user of nodemask here.
    > > > > + */
    > > > > + if (nodemask) {
    > > > > + nodemask_t mask;
    > > > > + /* check mempolicy's nodemask contains all N_HIGH_MEMORY */
    > > > > + nodes_and(mask, *nodemask, node_states[N_HIGH_MEMORY]);
    > > > > + if (!nodes_equal(mask, node_states[N_HIGH_MEMORY]))
    > > > > + return CONSTRAINT_MEMORY_POLICY;
    > > > > + }
    > > >
    > > > Although a nodemask_t was previously allocated on the stack, we should
    > > > probably change this to use NODEMASK_ALLOC() for kernels with higher
    > > > CONFIG_NODES_SHIFT since allocations can happen very deep into the stack.
    > >
    > > No. NODEMASK_ALLOC() is crap. we should remove it.
    >
    > I've booted 1K node systems and have found it to be helpful to ensure that
    > the stack will not overflow especially in areas where we normally are deep
    > already, such as in the page allocator.

    Linux doesn't support 1K nodes. (and only SGI huge machine use 512 nodes)

    At least, NODEMASK_ALLOC should make more cleaner interface. current one
    and struct nodemask_scratch are pretty ugly.


    > > btw, CPUMASK_ALLOC was already removed.
    >
    > I don't remember CPUMASK_ALLOC() actually being merged. I know the
    > comment exists in nodemask.h, but I don't recall any CPUMASK_ALLOC() users
    > in the tree.





    \
     
     \ /
      Last update: 2009-11-11 04:27    [W:0.025 / U:0.748 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site