I'm seeing a large number of allocation errors originating from the Mellanox IB driver when booting the 4.2-rc1 kernel on a 4096cpu 32TB memory system: 8<--- <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 64; reverting to legacy <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 65; reverting to legacy <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 66; reverting to legacy <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 67; reverting to legacy <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 68; reverting to legacy <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 69; reverting to legacy <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 70; reverting to legacy <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 71; reverting to legacy ...... <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 123; reverting to legacy --->8 Where the failing function is in drivers/infiniband/hw/mlx4/main.c: 8<--- 2042 static void mlx4_ib_alloc_eqs(struct mlx4_dev *dev, struct mlx4_ib_dev *ibdev) ... 2075 /* Set IRQ for specific name (per ring) */ 2076 if (mlx4_assign_eq(dev, name, NULL, 2077 &ibdev->eq_table[eq])) { 2078 /* Use legacy (same as mlx4_en driver) */ 2079 pr_warn("Can't allocate EQ %d; reverting to legacy\n", eq); 2080 ibdev->eq_table[eq] = 2081 (eq % dev->caps.num_comp_vectors); 2082 } --->8 The problem doesn't appear to be fatal. At this point I am unsure if this is actually expected behavior, so I'm looking for some insight into the issue. At first we believed the problem to be with request_irq, but after writing in some debug code that mlx4_assign_eq returned -28, indicating that vec was never assigned: 8<--- @@ -1401,6 +1402,7 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap, if (vec) { *vector = vec; } else { + pr_crit("!!! debug: mlx4_assign_eq - last err %d\n", err); *vector = 0; err = (i == dev->caps.comp_pool) ? -ENOSPC : err; } --->8 8<--- [ 1565.416273] !!! debug: mlx4_assign_eq - last err 0 [ 1565.416275] <mlx4_ib> mlx4_ib_alloc_eqs: !!! debug: mlx4_assign_eq returned -28 [ 1565.416277] <mlx4_ib> mlx4_ib_alloc_eqs: Can't allocate EQ 64; reverting to legacy --->8 Any help would be greatly appreciated! Andrew Banman -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html