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Use a stateful last_cpu approach to ensure unique core assignment when skipping CPU0. This avoids mapping multiple queues to the same core. Signed-off-by: Adrián García Casado --- .../intel/iwlwifi/pcie/gen1_2/trans.c | 20 ++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans.c index 4560d92d7..7077ec015 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans.c @@ -1672,18 +1672,28 @@ static void iwl_pcie_irq_set_affinity(struct iwl_trans *trans, struct iwl_trans_info *info) { #if defined(CONFIG_SMP) - int iter_rx_q, i, ret, cpu, offset; + int iter_rx_q, i, ret, cpu, offset, last_cpu; struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); i = trans_pcie->shared_vec_mask & IWL_SHARED_IRQ_FIRST_RSS ? 0 : 1; iter_rx_q = info->num_rxqs - 1 + i; - offset = 1 + i; + last_cpu = -1; for (; i < iter_rx_q ; i++) { /* - * Get the cpu prior to the place to search - * (i.e. return will be > i - 1). + * Balanced distribution: skip CPU0 for high-rate RSS queues + * to avoid contention with system housekeeping. */ - cpu = cpumask_next(i - offset, cpu_online_mask); + cpu = cpumask_next(last_cpu, cpu_online_mask); + if (cpu >= nr_cpu_ids) + cpu = cpumask_first(cpu_online_mask); + + if (cpu == 0 && num_online_cpus() > 1) { + cpu = cpumask_next(0, cpu_online_mask); + if (cpu >= nr_cpu_ids) + cpu = cpumask_first(cpu_online_mask); + } + last_cpu = cpu; + cpumask_set_cpu(cpu, &trans_pcie->affinity_mask[i]); ret = irq_set_affinity_hint(trans_pcie->msix_entries[i].vector, &trans_pcie->affinity_mask[i]); -- 2.47.3