Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [BUGFIX][PATCH] oom-kill: fix NUMA consraint check with nodemask v3 | Date | Wed, 11 Nov 2009 12:23:43 +0900 (JST) |
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> 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.
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