>-----Original Message-----
>From: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
>Sent: Thursday, November 16, 2023 4:25 AM
>To: Souradeep Chakrabarti <schakrabarti@xxxxxxxxxxxxxxxxxxx>; KY Srinivasan
><kys@xxxxxxxxxxxxx>; wei.liu@xxxxxxxxxx; Dexuan Cui <decui@xxxxxxxxxxxxx>;
>davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx;
>pabeni@xxxxxxxxxx; Long Li <longli@xxxxxxxxxxxxx>;
>sharmaajay@xxxxxxxxxxxxx; leon@xxxxxxxxxx; cai.huoqing@xxxxxxxxx;
>ssengar@xxxxxxxxxxxxxxxxxxx; vkuznets@xxxxxxxxxx; tglx@xxxxxxxxxxxxx; linux-
>hyperv@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
>linux-rdma@xxxxxxxxxxxxxxx
>Cc: Souradeep Chakrabarti <schakrabarti@xxxxxxxxxxxxx>; Paul Rosswurm
><paulros@xxxxxxxxxxxxx>
>Subject: RE: [PATCH net-next] net: mana: Assigning IRQ affinity on HT cores
>
>
>
>> -----Original Message-----
>> From: Souradeep Chakrabarti <schakrabarti@xxxxxxxxxxxxxxxxxxx>
>> Sent: Wednesday, November 15, 2023 8:49 AM
>> To: KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang
>> <haiyangz@xxxxxxxxxxxxx>; wei.liu@xxxxxxxxxx; Dexuan Cui
>> <decui@xxxxxxxxxxxxx>; davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx;
>> kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx; Long Li <longli@xxxxxxxxxxxxx>;
>> sharmaajay@xxxxxxxxxxxxx; leon@xxxxxxxxxx; cai.huoqing@xxxxxxxxx;
>> ssengar@xxxxxxxxxxxxxxxxxxx; vkuznets@xxxxxxxxxx; tglx@xxxxxxxxxxxxx;
>> linux-hyperv@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
>> kernel@xxxxxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx
>> Cc: Souradeep Chakrabarti <schakrabarti@xxxxxxxxxxxxx>; Paul Rosswurm
>> <paulros@xxxxxxxxxxxxx>; Souradeep Chakrabarti
>> <schakrabarti@xxxxxxxxxxxxxxxxxxx>
>> Subject: [PATCH net-next] net: mana: Assigning IRQ affinity on HT
>> cores
>>
>> Existing MANA design assigns IRQ affinity to every sibling CPUs, which
>> causes IRQ coalescing and may reduce the network performance with RSS.
>>
>> Improve the performance by adhering the configuration for RSS, which
>> prioritise IRQ affinity on HT cores.
>>
>> Signed-off-by: Souradeep Chakrabarti
>> <schakrabarti@xxxxxxxxxxxxxxxxxxx>
>> ---
>> .../net/ethernet/microsoft/mana/gdma_main.c | 126 ++++++++++++++++-
>> -
>> 1 file changed, 117 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c
>> b/drivers/net/ethernet/microsoft/mana/gdma_main.c
>> index 6367de0c2c2e..839be819d46e 100644
>> --- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
>> +++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
>> @@ -1243,13 +1243,115 @@ void mana_gd_free_res_map(struct
>> gdma_resource *r)
>> r->size = 0;
>> }
>>
>> +static void cpu_mask_set(cpumask_var_t *filter_mask, cpumask_var_t
>> **filter_mask_list)
>> +{
>> + unsigned int core_count = 0, cpu;
>> + cpumask_var_t *filter_mask_list_tmp;
>> +
>> + BUG_ON(!filter_mask || !filter_mask_list);
>> + filter_mask_list_tmp = *filter_mask_list;
>> + cpumask_copy(*filter_mask, cpu_online_mask);
>> + /* for each core create a cpumask lookup table,
>> + * which stores all the corresponding siblings
>> + */
>> + for_each_cpu(cpu, *filter_mask) {
>> +
>> BUG_ON(!alloc_cpumask_var(&filter_mask_list_tmp[core_count],
>> GFP_KERNEL));
>> + cpumask_or(filter_mask_list_tmp[core_count],
>> filter_mask_list_tmp[core_count],
>> + topology_sibling_cpumask(cpu));
>> + cpumask_andnot(*filter_mask, *filter_mask,
>> topology_sibling_cpumask(cpu));
>> + core_count++;
>> + }
>> +}
>> +
>> +static int irq_setup(int *irqs, int nvec) {
>> + cpumask_var_t filter_mask;
>> + cpumask_var_t *filter_mask_list;
>> + unsigned int cpu_first, cpu, irq_start, cores = 0;
>> + int i, core_count = 0, numa_node, cpu_count = 0, err = 0;
>> +
>> + BUG_ON(!alloc_cpumask_var(&filter_mask, GFP_KERNEL));
>> + cpus_read_lock();
>> + cpumask_copy(filter_mask, cpu_online_mask);
>> + /* count the number of cores
>> + */
>> + for_each_cpu(cpu, filter_mask) {
>> + cpumask_andnot(filter_mask, filter_mask,
>> topology_sibling_cpumask(cpu));
>> + cores++;
>> + }
>> + filter_mask_list = kcalloc(cores, sizeof(cpumask_var_t), GFP_KERNEL);
>> + if (!filter_mask_list) {
>> + err = -ENOMEM;
>> + goto free_irq;
>> + }
>> + /* if number of cpus are equal to max_queues per port, then
>> + * one extra interrupt for the hardware channel communication.
>> + */
>> + if (nvec - 1 == num_online_cpus()) {
>> + irq_start = 1;
>> + cpu_first = cpumask_first(cpu_online_mask);
>> + irq_set_affinity_and_hint(irqs[0], cpumask_of(cpu_first));
>> + } else {
>> + irq_start = 0;
>> + }
>> + /* reset the core_count and num_node to 0.
>> + */
>> + core_count = 0;
>> + numa_node = 0;
>
>Please start with gc->numa_node here. I know it's 0 for now. But the host will
>provide real numa node# close to the device in the future.
Thank you. Will take care of it in next version.
>
>Also, as we discussed, consider using the NUMA distance to select the next numa
>node (in a separate patch).
>
>> + cpu_mask_set(&filter_mask, &filter_mask_list);
>> + /* for each interrupt find the cpu of a particular
>> + * sibling set and if it belongs to the specific numa
>> + * then assign irq to it and clear the cpu bit from
>> + * the corresponding sibling list from filter_mask_list.
>> + * Increase the cpu_count for that node.
>> + * Once all cpus for a numa node is assigned, then
>> + * move to different numa node and continue the same.
>> + */
>> + for (i = irq_start; i < nvec; ) {
>> + cpu_first = cpumask_first(filter_mask_list[core_count]);
>> + if (cpu_first < nr_cpu_ids && cpu_to_node(cpu_first) ==
>> numa_node) {
>> + irq_set_affinity_and_hint(irqs[i],
>> cpumask_of(cpu_first));
>> + cpumask_clear_cpu(cpu_first,
>> filter_mask_list[core_count]);
>> + cpu_count = cpu_count + 1;
>> + i = i + 1;
>> + /* checking if all the cpus are used from the
>> + * particular node.
>> + */
>> + if (cpu_count == nr_cpus_node(numa_node)) {
>> + numa_node = numa_node + 1;
>> + if (numa_node == num_online_nodes()) {
>> + cpu_mask_set(&filter_mask,
>> &filter_mask_list);
>> + numa_node = 0;
>Ditto.
>
>Other things look good to me.
>
>Thanks,
>- Haiyang
