Messages in this thread | | | Date | Mon, 2 Nov 2009 12:05:09 -0500 (EST) | From | Christoph Lameter <> | Subject | Re: [RFC][-mm][PATCH 1/6] oom-killer: updates for classification of OOM |
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On Mon, 2 Nov 2009, KAMEZAWA Hiroyuki wrote:
> /* > - * Types of limitations to the nodes from which allocations may occur > + * Types of limitations to zones from which allocations may occur > */
"Types of limitations that may cause OOMs"? MEMCG limitations are not zone based.
> */ > > -unsigned long badness(struct task_struct *p, unsigned long uptime) > +static unsigned long __badness(struct task_struct *p, > + unsigned long uptime, enum oom_constraint constraint, > + struct mem_cgroup *mem) > { > unsigned long points, cpu_time, run_time; > struct mm_struct *mm;
Why rename this function? You are adding a global_badness anyways.
> + /* > + * In numa environ, almost all allocation will be against NORMAL zone.
The typical allocations will be against the policy_zone! SGI IA64 (and others) have policy_zone == GFP_DMA.
> + * But some small area, ex)GFP_DMA for ia64 or GFP_DMA32 for x86-64 > + * can cause OOM. We can use policy_zone for checking lowmem. > + */
Simply say that we are checking if the zone constraint is below the policy zone?
> + * Now, only mempolicy specifies nodemask. But if nodemask > + * covers all nodes, this oom is global oom. > + */ > + if (nodemask && !nodes_equal(node_states[N_HIGH_MEMORY], *nodemask)) > + ret = CONSTRAINT_MEMORY_POLICY;
Huh? A cpuset can also restrict the nodes?
> + /* > + * If not __GFP_THISNODE, zonelist containes all nodes. And if
Dont see any __GFP_THISNODE checks here.
> panic("out of memory from page fault. panic_on_oom is selected.\n"); > > read_lock(&tasklist_lock); > - __out_of_memory(0, 0); /* unknown gfp_mask and order */ > + /* > + * Considering nature of pages required for page-fault,this must be > + * global OOM (if not cpuset...). Then, CONSTRAINT_NONE is correct. > + * zonelist, nodemasks are unknown... > + */ > + __out_of_memory(0, CONSTRAINT_NONE, 0, NULL); > read_unlock(&tasklist_lock);
Page faults can occur on processes that have memory restrictions.
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