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Commit cdb08f8f authored by Ben Hutchings's avatar Ben Hutchings
Browse files

sfc: Set default parallelism to per-core by default 



The previous default of per-package can be more CPU-efficient, but
users generally seem to prefer per-core.  It should also allow
accelerated RFS to direct packets more precisely, if IRQ affinity
is properly spread out.

Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
parent fa142b9d

drivers/net/ethernet/sfc/efx.c

+7 −7
Original line number Diff line number Diff line
@@ -162,7 +162,7 @@ static unsigned int interrupt_mode; 
 * interrupt handling.

 *

 * Cards without MSI-X will only target one CPU via legacy or MSI interrupt.

 * The default (0) means to assign an interrupt to each package (level II cache)

 * The default (0) means to assign an interrupt to each core.

 */

static unsigned int rss_cpus;

module_param(rss_cpus, uint, 0444);
@@ -1148,14 +1148,14 @@ static void efx_fini_io(struct efx_nic *efx) 


static int efx_wanted_parallelism(void)

{

	cpumask_var_t core_mask;

	cpumask_var_t thread_mask;

	int count;

	int cpu;



	if (rss_cpus)

		return rss_cpus;



	if (unlikely(!zalloc_cpumask_var(&core_mask, GFP_KERNEL))) {

	if (unlikely(!zalloc_cpumask_var(&thread_mask, GFP_KERNEL))) {

		printk(KERN_WARNING

		       "sfc: RSS disabled due to allocation failure\n");

		return 1;
@@ -1163,14 +1163,14 @@ static int efx_wanted_parallelism(void) 


	count = 0;

	for_each_online_cpu(cpu) {

		if (!cpumask_test_cpu(cpu, core_mask)) {

		if (!cpumask_test_cpu(cpu, thread_mask)) {

			++count;

			cpumask_or(core_mask, core_mask,

				   topology_core_cpumask(cpu));

			cpumask_or(thread_mask, thread_mask,

				   topology_thread_cpumask(cpu));

		}

	}



	free_cpumask_var(core_mask);

	free_cpumask_var(thread_mask);

	return count;

}