Github user jpeach commented on a diff in the pull request:
https://github.com/apache/trafficserver/pull/956#discussion_r77443787
--- Diff: iocore/eventsystem/UnixEventProcessor.cc ---
@@ -152,6 +155,59 @@ EventProcessor::start(int n_event_threads, size_t
stacksize)
#else
Debug("iocore_thread", "EThread: %d %s: %d", i, obj_name,
obj->logical_index);
#endif // HWLOC_API_VERSION
+ }
+#endif // TS_USE_HWLOC
+
+ snprintf(thr_name, MAX_THREAD_NAME_LENGTH, "[ET_NET %d]", i);
+#if TS_USE_HWLOC
+ if (obj_count > 0) {
+ hwloc_membind_policy_t mem_policy = HWLOC_MEMBIND_DEFAULT;
+ hwloc_nodeset_t nodeset = hwloc_bitmap_alloc();
+ int num_nodes = 0;
+
+ hwloc_cpuset_to_nodeset(ink_get_topology(), obj->cpuset, nodeset);
+ num_nodes =
hwloc_get_nbobjs_inside_cpuset_by_type(ink_get_topology(), obj->cpuset,
HWLOC_OBJ_NODE);
+
+ if (num_nodes == 1) {
+ mem_policy = HWLOC_MEMBIND_BIND;
+ } else if (num_nodes > 1) {
+ mem_policy = HWLOC_MEMBIND_INTERLEAVE;
+ }
+
+ if (mem_policy != HWLOC_MEMBIND_DEFAULT) {
+ hwloc_set_membind_nodeset(ink_get_topology(), nodeset, mem_policy,
HWLOC_MEMBIND_THREAD);
+ }
--- End diff --
If I understand this correctly, we swizzle the memory allocation policy for
the thread so that the subsequent allocations for the stacks will be
interleaved across nodes.
Does this depend on the mechanics of how ``malloc(3)`` chooses to allocate?
Why do we have to figure this out for each thread? Can we just do it once
then allocate all the stacks?
Why do we even bother with ``HWLOC_MEMBIND_BIND``? If there's only 1 node,
it seems like it would have to bind memory to that node?
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