sfc: Create one RX queue and interrupt per CPU package by default

Using multiple cores in the same package to handle received traffic
does not appear to provide a performance benefit.  Therefore use CPU
topology information to count CPU packages and use that as the default
number of RX queues and interrupts.  We rely on interrupt balancing to
spread the interrupts across packages.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Ben Hutchings 2008-07-18 19:03:10 +01:00 committed by Jeff Garzik
parent 8d9853d911
commit aa6ef27ea9

View File

@ -19,6 +19,7 @@
#include <linux/in.h>
#include <linux/crc32.h>
#include <linux/ethtool.h>
#include <linux/topology.h>
#include "net_driver.h"
#include "gmii.h"
#include "ethtool.h"
@ -832,7 +833,23 @@ static void efx_probe_interrupts(struct efx_nic *efx)
if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
BUG_ON(!pci_find_capability(efx->pci_dev, PCI_CAP_ID_MSIX));
efx->rss_queues = rss_cpus ? rss_cpus : num_online_cpus();
if (rss_cpus == 0) {
cpumask_t core_mask;
int cpu;
cpus_clear(core_mask);
efx->rss_queues = 0;
for_each_online_cpu(cpu) {
if (!cpu_isset(cpu, core_mask)) {
++efx->rss_queues;
cpus_or(core_mask, core_mask,
topology_core_siblings(cpu));
}
}
} else {
efx->rss_queues = rss_cpus;
}
efx->rss_queues = min(efx->rss_queues, max_channel + 1);
efx->rss_queues = min(efx->rss_queues, EFX_MAX_CHANNELS);