> -----Original Message-----
> From: Jerin Jacob <jerinjac...@gmail.com>
> Sent: Tuesday 17 June 2025 16:50
>
> > > > -struct __rte_cache_aligned rte_graph_cluster_node_stats {
> > > > +struct rte_graph_cluster_node_stats {
> > >
> > > This is a fastpath structure. No need to change the alignment here.
> >
> > rte_graph_cluster_stats includes it, so unfortunately would stay cache-
> aligned regardless of the attributes unless we make
> rte_graph_cluster_node_stats default-aligned as well. If you are sure that
> we need to keep node one cache-aligned we can return to rte_malloc
> solution (or posix_memalign, but I would prefer not to hand-code aligned
> realloc).
>
> I think, existing following code will take care of this. Are you
> seeing the sanitizer issue if the change is only updating
> rte_graph_cluster_stats alignment?
Yes, still seeing the sanitizer issue. And if fails even before reaching
clusters, on the struct rte_graph_cluster_stats itself because I believe
alignment propagates from members to enclosing structs.
> /* For a given cluster, max nodes will be the max number of graphs */
> cluster_node_size += cluster->nb_graphs * sizeof(struct rte_node *);
> cluster_node_size = RTE_ALIGN(cluster_node_size,
> RTE_CACHE_LINE_SIZE);
Please correct me if I am wrong, AFAIU it looks like this in memory:
- rte_graph_cluster_stats
- cluster_node
- rte_graph_cluster_node_stats
- rte_node *[nb_graphs]
- padding of rte_node pointers array to cacheline
- cluster_node
- rte_graph_cluster_node_stats
- rte_node *[nb_graphs]...
cluster_node_size calculation above ensures correct distance between
cluster_node structs due to presence of the rte_node pointers arrays in
between, but alignment of the first cluster_node still depends on the alignment
of rte_graph_cluster_stats, and each of the next ones depends on the previous.
We could of course re-align the first one manually (in each loop, after
allocating some extra space), but to me it looks like the job rte_malloc could
easier do for us. What do you think would be the right way forward?
